TBD Meeting (2840-21)

Pregnant patients with COVID-19 infections were more likely to experience severe disease if they had preexisting comorbidities, such as chronic hypertension, asthma, or pregestational diabetes, according to findings from a new study presented at the meeting sponsored by the Society for Maternal-Fetal Medicine.

The study included outcomes for the largest multistate cohort of pregnant patients with COVID-19 outside of what the Centers for Disease Control and Prevention is tracking. Its findings also mirrored those of a multicenter, retrospective study in Washington state, published in the American Journal of Obstetrics & Gynecology. That study also found that pregnant patients hospitalized for COVID-19 were more likely to have comorbidities, and both studies found an increased likelihood of preterm birth among pregnant patients with severe or critical disease.
 

Disease severity linked to risk of perinatal complications

In the abstract presented at the SMFM meeting, more severe disease was associated with older age and a higher median body mass index, as seen in the general population, but the researchers found no differences in disease severity occurred by race or ethnicity, Torri D. Metz, MD, of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network, told attendees of the conference. The researchers also found that perinatal complications were more prevalent in those with severe or critical COVID-19 disease but not in those with mild or moderate disease. Vertical COVID-19 transmission from mother to child was rare.

The observational study included all patients who had a singleton pregnancy, had a positive SARS-CoV-2 test, and delivered between March 1 and July 31, 2020, at one of the 33 U.S. hospitals in the NICHD Maternal-Fetal Medicine Units Network, spread across 14 states. The researchers used electronic medical records to determine incidence of cesarean delivery, postpartum hemorrhage, hypertensive disorders of pregnancy, preterm birth (less than 37 weeks), maternal death, infant death, and positive infant COVID-19 test. They tracked mothers through 6 weeks post partum and newborns through delivery hospitalization.

Of 1,291 patients in the cohort, 1,219 received their first positive COVID-19 test during pregnancy. The others tested positive while in the hospital for delivery or within a month and a half after discharge. Limiting their analysis to those who developed COVID-19 while pregnant prior to delivery, nearly half (47%) were asymptomatic.

The disease was mild in 27%, moderate in 14%, severe in 8%, and critical in 4%. The researchers used the National Institutes of Health classifications for severity and included deaths in the critical group. The most common symptom was a cough, reported by a third of the patients (34%). Four of six maternal deaths that occurred were caused by COVID-19.

Compared with an average age of 28 in those without symptoms, the mean age was 29 in those with mild/moderate disease and 30 in those with severe/critical disease (P = .006). Similarly, the mean BMI was 28.3 in asymptomatic patients, 29 in those with mild/moderate disease, and 32.3 in those with severe/critical disease (P < .001). Despite a diverse cohort – 53% Hispanic, 23% Black, and 15% White – the researches found no racial/ethnic trends in disease severity.

Patients who had asthma, chronic obstructive pulmonary disorder, pregestational diabetes, chronic hypertension, chronic liver disease, or a seizure disorder were all significantly more likely to have critical/severe disease than mild/moderate disease, and more likely to have mild/moderate disease than asymptomatic (P values ranged from < .001 to .02).

The mothers with critical or severe illness were 1.6 times more likely to have cesarean births and to have hypertensive disorders of pregnancy, and they were twice as likely to have postpartum hemorrhage (P < .001; P = .007). Those with mild or moderate disease, however, had no increased risks for perinatal complications over asymptomatic patients.

Critical or severe illness was also associated with more than triple the risk of preterm birth (adjusted risk ratio, 3.6; P < .001). Newborns of mothers with critical or severe illness also had three times greater risk of neonatal ICU admission (ARR, 3.1; P <. 001) and weighed an average 385 g less than newborns of asymptomatic mothers. COVID-19 rate among infants was only 1% during delivery hospitalization.

Since the study cutoff was July 30 and COVID infections only became prevalent in March, the researchers were unable to evaluate women for outcomes resulting from COVID infections in early pregnancy, such as congenital anomalies or early miscarriage, Dr. Metz said. In addition, since many of the sites are urban centers, the data may not be generalizable to rural areas.

Peter S. Bernstein, MD, MPH, of Montefiore Medical Center, New York, asked whether the increased cesarean deliveries and preterm births in the group of women with severe disease were caused by usual obstetric causes or the treatment of COVID-19 infection. Dr. Metz said the vast majority of preterm deliveries were indicated, but only a small proportion were induced for COVID-19 alone. “A lot had hypertensive disorders of pregnancies or PPROM, so it’s partly driven by the infection itself but also partly driven by some of those perinatal complications,” she said.
 

Similar findings in Washington

In the Washington study, among 240 pregnant patients with confirmed COVID-19 infection between March 1 and July 30, 2020, 1 in 11 developed severe or critical disease, and 1 in 10 were hospitalized. The pregnant patients had more than triple the risk of hospitalization compared with adults of similar ages in the general population (10% vs. 2.8%; rate ratio, 3.5). Similar to the multistate NICHD study, women were more likely to be hospitalized if they had asthma, hypertension, type 2 diabetes, autoimmune disease, or class III obesity.

Three mothers died of COVID-19, resulting in a case fatality rate 13.6 times greater than nonpregnant patients with COVID-19 in the general population. The absolute difference in the rate was 1.2%. As seen in the NICHD study, preterm birth was more common in mothers with severe or critical COVID-19. Nearly half (45.4%) of mothers with severe or critical COVID-19 delivered preterm compared to 5.2% in those with mild COVID-19 (P < .001).

“Our finding that deaths in pregnant patients contributed disproportionately to deaths from COVID-19 among 20- to 39-year-olds in Washington state is similar to what was observed during the influenza A virus H1N1 2009 pandemic,” Erica M. Lokken, PhD, MS, of the departments of global health and ob.gyn. at the University of Washington, Seattle, and colleagues wrote in the Washington study. But they noted that it took 8 months into the pandemic before pregnant patients were identified as a high-risk group for COVID-19.

“Given the similarity in clinical course between COVID-19 and IAV H1N1 2009 with an increased risk for mortality during pregnancy and the postpartum period, we strongly recommend that pregnant patients should be considered a high-risk population to novel highly pathogenic respiratory viruses until proven otherwise by population-based studies with good ascertainment of pregnancy status,” they wrote.

Judette Louis, MD, MPH, associate professor of ob.gyn. and department chair at the University of South Florida, Tampa, said in an interview that the findings in these studies were fairly expected, but it’s important to have data from such a large cohort as the one presented at SMFM.

“It confirmed that those who had severe disease were more likely to have chronic medical conditions, mirroring what we saw in the general population who isn’t pregnant,” Dr. Louis said. “I thought this was very crucial because as pregnant women are trying to decide whether they should get the COVID vaccine, this provides support to say that if you’re pregnant, you’re more likely to have severe disease [if you have] other chronic medical conditions.”

The findings also confirm the importance of pregnant people taking precautions to avoid infection.

“Even though these individuals are, as a group, in an age cohort that mostly has asymptomatic disease, for some of them, it results in severe disease and even maternal death,” she said. “They should still take it seriously if they’re pregnant.”

The SMFM abstract study was funded by the NICHD. The Washington study was funded by the University of Washington Population Health Initiative, the National Institutes of Health, and philanthropic gift funds. One coauthor of the Washington study is on a Pfizer and GlaxoSmithKline advisory board for immunizations. No other authors or individuals interviewed reported any disclosures.

Pregnant patients with COVID-19 infections were more likely to experience severe disease if they had preexisting comorbidities, such as chronic hypertension, asthma, or pregestational diabetes, according to findings from a new study presented at the meeting sponsored by the Society for Maternal-Fetal Medicine.

The study included outcomes for the largest multistate cohort of pregnant patients with COVID-19 outside of what the Centers for Disease Control and Prevention is tracking. Its findings also mirrored those of a multicenter, retrospective study in Washington state, published in the American Journal of Obstetrics & Gynecology. That study also found that pregnant patients hospitalized for COVID-19 were more likely to have comorbidities, and both studies found an increased likelihood of preterm birth among pregnant patients with severe or critical disease.
 

Disease severity linked to risk of perinatal complications

In the abstract presented at the SMFM meeting, more severe disease was associated with older age and a higher median body mass index, as seen in the general population, but the researchers found no differences in disease severity occurred by race or ethnicity, Torri D. Metz, MD, of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network, told attendees of the conference. The researchers also found that perinatal complications were more prevalent in those with severe or critical COVID-19 disease but not in those with mild or moderate disease. Vertical COVID-19 transmission from mother to child was rare.

The observational study included all patients who had a singleton pregnancy, had a positive SARS-CoV-2 test, and delivered between March 1 and July 31, 2020, at one of the 33 U.S. hospitals in the NICHD Maternal-Fetal Medicine Units Network, spread across 14 states. The researchers used electronic medical records to determine incidence of cesarean delivery, postpartum hemorrhage, hypertensive disorders of pregnancy, preterm birth (less than 37 weeks), maternal death, infant death, and positive infant COVID-19 test. They tracked mothers through 6 weeks post partum and newborns through delivery hospitalization.

Of 1,291 patients in the cohort, 1,219 received their first positive COVID-19 test during pregnancy. The others tested positive while in the hospital for delivery or within a month and a half after discharge. Limiting their analysis to those who developed COVID-19 while pregnant prior to delivery, nearly half (47%) were asymptomatic.

The disease was mild in 27%, moderate in 14%, severe in 8%, and critical in 4%. The researchers used the National Institutes of Health classifications for severity and included deaths in the critical group. The most common symptom was a cough, reported by a third of the patients (34%). Four of six maternal deaths that occurred were caused by COVID-19.

Compared with an average age of 28 in those without symptoms, the mean age was 29 in those with mild/moderate disease and 30 in those with severe/critical disease (P = .006). Similarly, the mean BMI was 28.3 in asymptomatic patients, 29 in those with mild/moderate disease, and 32.3 in those with severe/critical disease (P < .001). Despite a diverse cohort – 53% Hispanic, 23% Black, and 15% White – the researches found no racial/ethnic trends in disease severity.

Patients who had asthma, chronic obstructive pulmonary disorder, pregestational diabetes, chronic hypertension, chronic liver disease, or a seizure disorder were all significantly more likely to have critical/severe disease than mild/moderate disease, and more likely to have mild/moderate disease than asymptomatic (P values ranged from < .001 to .02).

The mothers with critical or severe illness were 1.6 times more likely to have cesarean births and to have hypertensive disorders of pregnancy, and they were twice as likely to have postpartum hemorrhage (P < .001; P = .007). Those with mild or moderate disease, however, had no increased risks for perinatal complications over asymptomatic patients.

Critical or severe illness was also associated with more than triple the risk of preterm birth (adjusted risk ratio, 3.6; P < .001). Newborns of mothers with critical or severe illness also had three times greater risk of neonatal ICU admission (ARR, 3.1; P <. 001) and weighed an average 385 g less than newborns of asymptomatic mothers. COVID-19 rate among infants was only 1% during delivery hospitalization.

Since the study cutoff was July 30 and COVID infections only became prevalent in March, the researchers were unable to evaluate women for outcomes resulting from COVID infections in early pregnancy, such as congenital anomalies or early miscarriage, Dr. Metz said. In addition, since many of the sites are urban centers, the data may not be generalizable to rural areas.

Peter S. Bernstein, MD, MPH, of Montefiore Medical Center, New York, asked whether the increased cesarean deliveries and preterm births in the group of women with severe disease were caused by usual obstetric causes or the treatment of COVID-19 infection. Dr. Metz said the vast majority of preterm deliveries were indicated, but only a small proportion were induced for COVID-19 alone. “A lot had hypertensive disorders of pregnancies or PPROM, so it’s partly driven by the infection itself but also partly driven by some of those perinatal complications,” she said.
 

Similar findings in Washington

In the Washington study, among 240 pregnant patients with confirmed COVID-19 infection between March 1 and July 30, 2020, 1 in 11 developed severe or critical disease, and 1 in 10 were hospitalized. The pregnant patients had more than triple the risk of hospitalization compared with adults of similar ages in the general population (10% vs. 2.8%; rate ratio, 3.5). Similar to the multistate NICHD study, women were more likely to be hospitalized if they had asthma, hypertension, type 2 diabetes, autoimmune disease, or class III obesity.

Three mothers died of COVID-19, resulting in a case fatality rate 13.6 times greater than nonpregnant patients with COVID-19 in the general population. The absolute difference in the rate was 1.2%. As seen in the NICHD study, preterm birth was more common in mothers with severe or critical COVID-19. Nearly half (45.4%) of mothers with severe or critical COVID-19 delivered preterm compared to 5.2% in those with mild COVID-19 (P < .001).

“Our finding that deaths in pregnant patients contributed disproportionately to deaths from COVID-19 among 20- to 39-year-olds in Washington state is similar to what was observed during the influenza A virus H1N1 2009 pandemic,” Erica M. Lokken, PhD, MS, of the departments of global health and ob.gyn. at the University of Washington, Seattle, and colleagues wrote in the Washington study. But they noted that it took 8 months into the pandemic before pregnant patients were identified as a high-risk group for COVID-19.

“Given the similarity in clinical course between COVID-19 and IAV H1N1 2009 with an increased risk for mortality during pregnancy and the postpartum period, we strongly recommend that pregnant patients should be considered a high-risk population to novel highly pathogenic respiratory viruses until proven otherwise by population-based studies with good ascertainment of pregnancy status,” they wrote.

Judette Louis, MD, MPH, associate professor of ob.gyn. and department chair at the University of South Florida, Tampa, said in an interview that the findings in these studies were fairly expected, but it’s important to have data from such a large cohort as the one presented at SMFM.

“It confirmed that those who had severe disease were more likely to have chronic medical conditions, mirroring what we saw in the general population who isn’t pregnant,” Dr. Louis said. “I thought this was very crucial because as pregnant women are trying to decide whether they should get the COVID vaccine, this provides support to say that if you’re pregnant, you’re more likely to have severe disease [if you have] other chronic medical conditions.”

The findings also confirm the importance of pregnant people taking precautions to avoid infection.

“Even though these individuals are, as a group, in an age cohort that mostly has asymptomatic disease, for some of them, it results in severe disease and even maternal death,” she said. “They should still take it seriously if they’re pregnant.”

The SMFM abstract study was funded by the NICHD. The Washington study was funded by the University of Washington Population Health Initiative, the National Institutes of Health, and philanthropic gift funds. One coauthor of the Washington study is on a Pfizer and GlaxoSmithKline advisory board for immunizations. No other authors or individuals interviewed reported any disclosures.

Pregnant patients with COVID-19 infections were more likely to experience severe disease if they had preexisting comorbidities, such as chronic hypertension, asthma, or pregestational diabetes, according to findings from a new study presented at the meeting sponsored by the Society for Maternal-Fetal Medicine.

The study included outcomes for the largest multistate cohort of pregnant patients with COVID-19 outside of what the Centers for Disease Control and Prevention is tracking. Its findings also mirrored those of a multicenter, retrospective study in Washington state, published in the American Journal of Obstetrics & Gynecology. That study also found that pregnant patients hospitalized for COVID-19 were more likely to have comorbidities, and both studies found an increased likelihood of preterm birth among pregnant patients with severe or critical disease.
 

Disease severity linked to risk of perinatal complications

In the abstract presented at the SMFM meeting, more severe disease was associated with older age and a higher median body mass index, as seen in the general population, but the researchers found no differences in disease severity occurred by race or ethnicity, Torri D. Metz, MD, of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network, told attendees of the conference. The researchers also found that perinatal complications were more prevalent in those with severe or critical COVID-19 disease but not in those with mild or moderate disease. Vertical COVID-19 transmission from mother to child was rare.

The observational study included all patients who had a singleton pregnancy, had a positive SARS-CoV-2 test, and delivered between March 1 and July 31, 2020, at one of the 33 U.S. hospitals in the NICHD Maternal-Fetal Medicine Units Network, spread across 14 states. The researchers used electronic medical records to determine incidence of cesarean delivery, postpartum hemorrhage, hypertensive disorders of pregnancy, preterm birth (less than 37 weeks), maternal death, infant death, and positive infant COVID-19 test. They tracked mothers through 6 weeks post partum and newborns through delivery hospitalization.

Of 1,291 patients in the cohort, 1,219 received their first positive COVID-19 test during pregnancy. The others tested positive while in the hospital for delivery or within a month and a half after discharge. Limiting their analysis to those who developed COVID-19 while pregnant prior to delivery, nearly half (47%) were asymptomatic.

The disease was mild in 27%, moderate in 14%, severe in 8%, and critical in 4%. The researchers used the National Institutes of Health classifications for severity and included deaths in the critical group. The most common symptom was a cough, reported by a third of the patients (34%). Four of six maternal deaths that occurred were caused by COVID-19.

Compared with an average age of 28 in those without symptoms, the mean age was 29 in those with mild/moderate disease and 30 in those with severe/critical disease (P = .006). Similarly, the mean BMI was 28.3 in asymptomatic patients, 29 in those with mild/moderate disease, and 32.3 in those with severe/critical disease (P < .001). Despite a diverse cohort – 53% Hispanic, 23% Black, and 15% White – the researches found no racial/ethnic trends in disease severity.

Patients who had asthma, chronic obstructive pulmonary disorder, pregestational diabetes, chronic hypertension, chronic liver disease, or a seizure disorder were all significantly more likely to have critical/severe disease than mild/moderate disease, and more likely to have mild/moderate disease than asymptomatic (P values ranged from < .001 to .02).

The mothers with critical or severe illness were 1.6 times more likely to have cesarean births and to have hypertensive disorders of pregnancy, and they were twice as likely to have postpartum hemorrhage (P < .001; P = .007). Those with mild or moderate disease, however, had no increased risks for perinatal complications over asymptomatic patients.

Critical or severe illness was also associated with more than triple the risk of preterm birth (adjusted risk ratio, 3.6; P < .001). Newborns of mothers with critical or severe illness also had three times greater risk of neonatal ICU admission (ARR, 3.1; P <. 001) and weighed an average 385 g less than newborns of asymptomatic mothers. COVID-19 rate among infants was only 1% during delivery hospitalization.

Since the study cutoff was July 30 and COVID infections only became prevalent in March, the researchers were unable to evaluate women for outcomes resulting from COVID infections in early pregnancy, such as congenital anomalies or early miscarriage, Dr. Metz said. In addition, since many of the sites are urban centers, the data may not be generalizable to rural areas.

Peter S. Bernstein, MD, MPH, of Montefiore Medical Center, New York, asked whether the increased cesarean deliveries and preterm births in the group of women with severe disease were caused by usual obstetric causes or the treatment of COVID-19 infection. Dr. Metz said the vast majority of preterm deliveries were indicated, but only a small proportion were induced for COVID-19 alone. “A lot had hypertensive disorders of pregnancies or PPROM, so it’s partly driven by the infection itself but also partly driven by some of those perinatal complications,” she said.
 

Similar findings in Washington

In the Washington study, among 240 pregnant patients with confirmed COVID-19 infection between March 1 and July 30, 2020, 1 in 11 developed severe or critical disease, and 1 in 10 were hospitalized. The pregnant patients had more than triple the risk of hospitalization compared with adults of similar ages in the general population (10% vs. 2.8%; rate ratio, 3.5). Similar to the multistate NICHD study, women were more likely to be hospitalized if they had asthma, hypertension, type 2 diabetes, autoimmune disease, or class III obesity.

Three mothers died of COVID-19, resulting in a case fatality rate 13.6 times greater than nonpregnant patients with COVID-19 in the general population. The absolute difference in the rate was 1.2%. As seen in the NICHD study, preterm birth was more common in mothers with severe or critical COVID-19. Nearly half (45.4%) of mothers with severe or critical COVID-19 delivered preterm compared to 5.2% in those with mild COVID-19 (P < .001).

“Our finding that deaths in pregnant patients contributed disproportionately to deaths from COVID-19 among 20- to 39-year-olds in Washington state is similar to what was observed during the influenza A virus H1N1 2009 pandemic,” Erica M. Lokken, PhD, MS, of the departments of global health and ob.gyn. at the University of Washington, Seattle, and colleagues wrote in the Washington study. But they noted that it took 8 months into the pandemic before pregnant patients were identified as a high-risk group for COVID-19.

“Given the similarity in clinical course between COVID-19 and IAV H1N1 2009 with an increased risk for mortality during pregnancy and the postpartum period, we strongly recommend that pregnant patients should be considered a high-risk population to novel highly pathogenic respiratory viruses until proven otherwise by population-based studies with good ascertainment of pregnancy status,” they wrote.

Judette Louis, MD, MPH, associate professor of ob.gyn. and department chair at the University of South Florida, Tampa, said in an interview that the findings in these studies were fairly expected, but it’s important to have data from such a large cohort as the one presented at SMFM.

“It confirmed that those who had severe disease were more likely to have chronic medical conditions, mirroring what we saw in the general population who isn’t pregnant,” Dr. Louis said. “I thought this was very crucial because as pregnant women are trying to decide whether they should get the COVID vaccine, this provides support to say that if you’re pregnant, you’re more likely to have severe disease [if you have] other chronic medical conditions.”

The findings also confirm the importance of pregnant people taking precautions to avoid infection.

“Even though these individuals are, as a group, in an age cohort that mostly has asymptomatic disease, for some of them, it results in severe disease and even maternal death,” she said. “They should still take it seriously if they’re pregnant.”

The SMFM abstract study was funded by the NICHD. The Washington study was funded by the University of Washington Population Health Initiative, the National Institutes of Health, and philanthropic gift funds. One coauthor of the Washington study is on a Pfizer and GlaxoSmithKline advisory board for immunizations. No other authors or individuals interviewed reported any disclosures.

Despite slightly decreasing numbers of pregnant women hospitalized with influenza, the rate of morbidity among those who do have influenza has substantially increased from 2000 to 2015, likely due in part to an increase in comorbidities.

Maternal patients who have influenza while hospitalized for delivery are twice as likely to develop severe maternal morbidity than are those without influenza, according to findings from a new study presented at the Pregnancy Meeting, sponsored by the Society for Maternal-Fetal Medicine.

Pregnant women were also at substantially greater risk of sepsis or shock, needing mechanical ventilation, and acute respiratory distress syndrome. In fact, rates of overall severe maternal morbidity and of influenza-related complications have increased in maternal patients with influenza by more than 200% from 2000 to 2015.

“It was striking to see how the rate of delivery hospitalizations complicated by influenza has remained relatively stable with a small decline, but the rates of severe maternal morbidity were increasing and so markedly among those with influenza,” Timothy Wen, MD, MPH, a maternal-fetal medicine clinical fellow at the University of California, San Francisco, said in an interview. “The findings suggest that influenza may either be a contributor to rising rates of severe maternal morbidity or synergistically amplifying existing comorbidities to worsen outcomes,” he said during his presentation.

The increased risk of influenza complications in pregnant women became particularly apparent during the 2009-2010 H1N1 influenza pandemic. “Physiologic and immunologic changes predispose pregnant patients to higher risk for complications such as pneumonia, intensive care unit admission, and inpatient mortality,” Dr. Wen told attendees. But data have been scarce since H1N1.

The researchers conducted a cross-sectional analysis of delivery hospitalizations from 2000 to 2015 using the Nationwide Inpatient Sample, which includes about 20% of all U.S. inpatient hospitalizations from all payers. They looked at all maternal patients aged 15-54 who had a diagnosis of influenza. In looking at potential associations between influenza and morbidity, they adjusted their calculations for maternal age, payer status, median income, and race/ethnicity as well as the hospital factors of location, teaching status, and region. They also adjusted for a dozen clinical factors.

Of 62.7 million hospitalizations, 0.67% involved severe maternal mortality, including the following influenza complications:

• 0.02% with shock/sepsis.
• 0.01% needing mechanical ventilation.
• 0.04% with acute respiratory distress syndrome.

The 182,228 patients with influenza represented a rate of 29 cases per 10,000 deliveries, and 2.09% of them involved severe maternal morbidity, compared to severe maternal morbidity in just 0.66% of deliveries without influenza.

When looking specifically at rates of shock/sepsis, mechanical ventilation, and acute respiratory distress syndrome, the data revealed similar trends, with substantially higher proportions of patients with influenza experiencing these complications compared to maternal patients without influenza. For example, 0.3% of patients with influenza developed shock/sepsis whereas only 0.04% of patients without influenza did. Acute respiratory distress syndrome was similarly more common in patients with flu (0.45% vs. 0.04%), as was the need for mechanical ventilation (0.09% vs. 0.01%).

During the 15-year study period, the rate of maternal hospitalizations with influenza infections declined about 1.5%, from 30 to 24 per 10,000 deliveries. But trends with severe maternal morbidity in patients with influenza went in the other direction, increasing more than 200% over 15 years, from 100 to 342 cases of severe maternal morbidity per 10,000 patients with influenza. An increase also occurred in patients without influenza, but it was more modest, a nearly 50% increase, from 53 to 79 cases per 10,000 hospitalizations.

From year to year, severe maternal morbidity increased 5.3% annually among hospitalizations with influenza – more than twice the rate of a 2.4% annual increase among hospitalizations without influenza.

The researchers found that influenza is linked to twice the risk of severe maternal morbidity (adjusted risk ratio [aRR] = 2.08, P < .01). There were similarly higher risks with influenza of sepsis/shock (aRR = 3.23), mechanical ventilation (aRR = 6.04), and acute respiratory distress syndrome (aRR = 5.76; all P < .01).

Among the possible reasons for the increase in influenza morbidity – despite a decrease in influenza infections in this population – is the increase in the medical complexity of the patient population, Dr. Wen said.

“Patients who are getting pregnant today likely have more comorbid conditions (chronic hypertension, obesity, pregestational diabetes mellitus, etc.) than they did decades prior,” Dr. Wen said. “Clinically, it means that we have a baseline patient population at a higher risk of susceptibility for influenza and its complications.”

Maternal influenza immunization rates have meanwhile stagnated, Dr. Wen added. Influenza “is something that we know is preventable, or at least mitigated, by a vaccine,” he said. “Our results serve as a reminder for clinicians to continue counseling on the importance of influenza vaccination among pregnant patients, and even in those who are planning to become pregnant.”

He said these findings suggest the need for a low threshold for treating pregnant patients who have influenza symptoms with over-the-counter therapies or closely monitoring them.

Adetola Louis-Jacques, MD, of the University of South Florida, Tampa, found the increase in morbidity in those with flu particularly unexpected and concerning.

Despite slightly decreasing numbers of pregnant women hospitalized with influenza, the rate of morbidity among those who do have influenza has substantially increased from 2000 to 2015, likely due in part to an increase in comorbidities.

Maternal patients who have influenza while hospitalized for delivery are twice as likely to develop severe maternal morbidity than are those without influenza, according to findings from a new study presented at the Pregnancy Meeting, sponsored by the Society for Maternal-Fetal Medicine.

Pregnant women were also at substantially greater risk of sepsis or shock, needing mechanical ventilation, and acute respiratory distress syndrome. In fact, rates of overall severe maternal morbidity and of influenza-related complications have increased in maternal patients with influenza by more than 200% from 2000 to 2015.

“It was striking to see how the rate of delivery hospitalizations complicated by influenza has remained relatively stable with a small decline, but the rates of severe maternal morbidity were increasing and so markedly among those with influenza,” Timothy Wen, MD, MPH, a maternal-fetal medicine clinical fellow at the University of California, San Francisco, said in an interview. “The findings suggest that influenza may either be a contributor to rising rates of severe maternal morbidity or synergistically amplifying existing comorbidities to worsen outcomes,” he said during his presentation.

The increased risk of influenza complications in pregnant women became particularly apparent during the 2009-2010 H1N1 influenza pandemic. “Physiologic and immunologic changes predispose pregnant patients to higher risk for complications such as pneumonia, intensive care unit admission, and inpatient mortality,” Dr. Wen told attendees. But data have been scarce since H1N1.

The researchers conducted a cross-sectional analysis of delivery hospitalizations from 2000 to 2015 using the Nationwide Inpatient Sample, which includes about 20% of all U.S. inpatient hospitalizations from all payers. They looked at all maternal patients aged 15-54 who had a diagnosis of influenza. In looking at potential associations between influenza and morbidity, they adjusted their calculations for maternal age, payer status, median income, and race/ethnicity as well as the hospital factors of location, teaching status, and region. They also adjusted for a dozen clinical factors.

Of 62.7 million hospitalizations, 0.67% involved severe maternal mortality, including the following influenza complications:

• 0.02% with shock/sepsis.
• 0.01% needing mechanical ventilation.
• 0.04% with acute respiratory distress syndrome.

The 182,228 patients with influenza represented a rate of 29 cases per 10,000 deliveries, and 2.09% of them involved severe maternal morbidity, compared to severe maternal morbidity in just 0.66% of deliveries without influenza.

When looking specifically at rates of shock/sepsis, mechanical ventilation, and acute respiratory distress syndrome, the data revealed similar trends, with substantially higher proportions of patients with influenza experiencing these complications compared to maternal patients without influenza. For example, 0.3% of patients with influenza developed shock/sepsis whereas only 0.04% of patients without influenza did. Acute respiratory distress syndrome was similarly more common in patients with flu (0.45% vs. 0.04%), as was the need for mechanical ventilation (0.09% vs. 0.01%).

During the 15-year study period, the rate of maternal hospitalizations with influenza infections declined about 1.5%, from 30 to 24 per 10,000 deliveries. But trends with severe maternal morbidity in patients with influenza went in the other direction, increasing more than 200% over 15 years, from 100 to 342 cases of severe maternal morbidity per 10,000 patients with influenza. An increase also occurred in patients without influenza, but it was more modest, a nearly 50% increase, from 53 to 79 cases per 10,000 hospitalizations.

From year to year, severe maternal morbidity increased 5.3% annually among hospitalizations with influenza – more than twice the rate of a 2.4% annual increase among hospitalizations without influenza.

The researchers found that influenza is linked to twice the risk of severe maternal morbidity (adjusted risk ratio [aRR] = 2.08, P < .01). There were similarly higher risks with influenza of sepsis/shock (aRR = 3.23), mechanical ventilation (aRR = 6.04), and acute respiratory distress syndrome (aRR = 5.76; all P < .01).

Among the possible reasons for the increase in influenza morbidity – despite a decrease in influenza infections in this population – is the increase in the medical complexity of the patient population, Dr. Wen said.

“Patients who are getting pregnant today likely have more comorbid conditions (chronic hypertension, obesity, pregestational diabetes mellitus, etc.) than they did decades prior,” Dr. Wen said. “Clinically, it means that we have a baseline patient population at a higher risk of susceptibility for influenza and its complications.”

Maternal influenza immunization rates have meanwhile stagnated, Dr. Wen added. Influenza “is something that we know is preventable, or at least mitigated, by a vaccine,” he said. “Our results serve as a reminder for clinicians to continue counseling on the importance of influenza vaccination among pregnant patients, and even in those who are planning to become pregnant.”

He said these findings suggest the need for a low threshold for treating pregnant patients who have influenza symptoms with over-the-counter therapies or closely monitoring them.

Adetola Louis-Jacques, MD, of the University of South Florida, Tampa, found the increase in morbidity in those with flu particularly unexpected and concerning.

Despite slightly decreasing numbers of pregnant women hospitalized with influenza, the rate of morbidity among those who do have influenza has substantially increased from 2000 to 2015, likely due in part to an increase in comorbidities.

Maternal patients who have influenza while hospitalized for delivery are twice as likely to develop severe maternal morbidity than are those without influenza, according to findings from a new study presented at the Pregnancy Meeting, sponsored by the Society for Maternal-Fetal Medicine.

Pregnant women were also at substantially greater risk of sepsis or shock, needing mechanical ventilation, and acute respiratory distress syndrome. In fact, rates of overall severe maternal morbidity and of influenza-related complications have increased in maternal patients with influenza by more than 200% from 2000 to 2015.

“It was striking to see how the rate of delivery hospitalizations complicated by influenza has remained relatively stable with a small decline, but the rates of severe maternal morbidity were increasing and so markedly among those with influenza,” Timothy Wen, MD, MPH, a maternal-fetal medicine clinical fellow at the University of California, San Francisco, said in an interview. “The findings suggest that influenza may either be a contributor to rising rates of severe maternal morbidity or synergistically amplifying existing comorbidities to worsen outcomes,” he said during his presentation.

The increased risk of influenza complications in pregnant women became particularly apparent during the 2009-2010 H1N1 influenza pandemic. “Physiologic and immunologic changes predispose pregnant patients to higher risk for complications such as pneumonia, intensive care unit admission, and inpatient mortality,” Dr. Wen told attendees. But data have been scarce since H1N1.

The researchers conducted a cross-sectional analysis of delivery hospitalizations from 2000 to 2015 using the Nationwide Inpatient Sample, which includes about 20% of all U.S. inpatient hospitalizations from all payers. They looked at all maternal patients aged 15-54 who had a diagnosis of influenza. In looking at potential associations between influenza and morbidity, they adjusted their calculations for maternal age, payer status, median income, and race/ethnicity as well as the hospital factors of location, teaching status, and region. They also adjusted for a dozen clinical factors.

Of 62.7 million hospitalizations, 0.67% involved severe maternal mortality, including the following influenza complications:

• 0.02% with shock/sepsis.
• 0.01% needing mechanical ventilation.
• 0.04% with acute respiratory distress syndrome.

The 182,228 patients with influenza represented a rate of 29 cases per 10,000 deliveries, and 2.09% of them involved severe maternal morbidity, compared to severe maternal morbidity in just 0.66% of deliveries without influenza.

When looking specifically at rates of shock/sepsis, mechanical ventilation, and acute respiratory distress syndrome, the data revealed similar trends, with substantially higher proportions of patients with influenza experiencing these complications compared to maternal patients without influenza. For example, 0.3% of patients with influenza developed shock/sepsis whereas only 0.04% of patients without influenza did. Acute respiratory distress syndrome was similarly more common in patients with flu (0.45% vs. 0.04%), as was the need for mechanical ventilation (0.09% vs. 0.01%).

During the 15-year study period, the rate of maternal hospitalizations with influenza infections declined about 1.5%, from 30 to 24 per 10,000 deliveries. But trends with severe maternal morbidity in patients with influenza went in the other direction, increasing more than 200% over 15 years, from 100 to 342 cases of severe maternal morbidity per 10,000 patients with influenza. An increase also occurred in patients without influenza, but it was more modest, a nearly 50% increase, from 53 to 79 cases per 10,000 hospitalizations.

From year to year, severe maternal morbidity increased 5.3% annually among hospitalizations with influenza – more than twice the rate of a 2.4% annual increase among hospitalizations without influenza.

The researchers found that influenza is linked to twice the risk of severe maternal morbidity (adjusted risk ratio [aRR] = 2.08, P < .01). There were similarly higher risks with influenza of sepsis/shock (aRR = 3.23), mechanical ventilation (aRR = 6.04), and acute respiratory distress syndrome (aRR = 5.76; all P < .01).

Among the possible reasons for the increase in influenza morbidity – despite a decrease in influenza infections in this population – is the increase in the medical complexity of the patient population, Dr. Wen said.

“Patients who are getting pregnant today likely have more comorbid conditions (chronic hypertension, obesity, pregestational diabetes mellitus, etc.) than they did decades prior,” Dr. Wen said. “Clinically, it means that we have a baseline patient population at a higher risk of susceptibility for influenza and its complications.”

Maternal influenza immunization rates have meanwhile stagnated, Dr. Wen added. Influenza “is something that we know is preventable, or at least mitigated, by a vaccine,” he said. “Our results serve as a reminder for clinicians to continue counseling on the importance of influenza vaccination among pregnant patients, and even in those who are planning to become pregnant.”

He said these findings suggest the need for a low threshold for treating pregnant patients who have influenza symptoms with over-the-counter therapies or closely monitoring them.

Adetola Louis-Jacques, MD, of the University of South Florida, Tampa, found the increase in morbidity in those with flu particularly unexpected and concerning.

While the likelihood of a cesarean delivery usually drops as maternal education level increases, the disparities seen in cesarean rates between White and Black or Hispanic women actually increase with more maternal education, according to findings from a new study presented at the Pregnancy Meeting sponsored by the Society for Maternal-Fetal Medicine.

Typically, higher maternal education is associated with a lower likelihood of cesarean delivery, but this protective effect is much smaller for Black women and nonexistent for Hispanic women, leading to bigger gaps between these groups and White women, found Yael Eliner, MD, an ob.gyn. residency applicant at Boston University who conducted this research with her colleagues in the ob.gyn. department at Lenox Hill Hospital, New York, and Hofstra University, Hempstead, N.Y..

Researchers have previously identified racial and ethnic disparities in a wide range of maternal outcomes, including mortality, overall morbidity, preterm birth, low birth weight, fetal growth restriction, hypertensive disorders of pregnancy, diabetes, and cesarean deliveries. But the researchers wanted to know if the usual protective effects seen for cesarean deliveries existed in the racial and ethnic groups with these disparities. Past studies have already found that the protective effect of maternal education is greater for White women than Black women with infant mortality and overall self-rated health.

The researchers conducted a retrospective analysis of all low-risk nulliparous, term, singleton, vertex live births to U.S. residents from 2016 to 2019 by using the natality database of the Centers for Disease Control and Prevention. They looked only at women who were non-Hispanic White, non-Hispanic Black, non-Hispanic Asian, and Hispanic women. They excluded women with pregestational and gestational diabetes, chronic hypertension, and hypertensive disorders of pregnancy.

Maternal education levels were stratified into those without a high school diploma, high school graduates (including those with some college credit), college graduates, and those with advanced degrees. The total population included 2,969,207 mothers with a 23.4% cesarean delivery rate.

Before considering education or other potential confounders, the cesarean delivery rate was 27.4% in Black women and 25.6% in Asian women, compared with 22.4% in White women and 23% in Hispanic women (P < .001).

Among those with less than a high school education, Black (20.9%), Asian (23.1%), and Hispanic (17.9% cesarean delivery prevalence was greater than that among White women (17.2%) (P < .001). The same was true among those with a high school education (with or without some college): 22% of White women in this group had cesarean deliveries compared with 26.3% of Black women, 26.3% of Asian women, and 22.5% of Hispanic women (P < .001).

At higher levels of education, the disparities not only persisted but actually increased.

The prevalence of cesarean deliveries was 23% in White college graduates, compared with 32.5% of Black college graduates, 26.3% of Asian college graduates, and 27.7% of Hispanic college graduates (P < .001). Similarly, in those with an advanced degree, the prevalence of cesarean deliveries in their population set was 23.6% of Whites, 36.3% of Blacks, 26.1% of Asians, and 30.1% of Hispanics (P < .001).

After adjusting for maternal education as well as age, prepregnancy body mass index, weight gain during pregnancy, insurance type, and neonatal birth weight, the researchers still found substantial disparities in cesarean delivery rates. Black women had 1.54 times greater odds of cesarean delivery than White women (P < .001). Similarly, the odds were 1.45 times greater for Asian women and 1.24 times greater for Hispanic women (P < .001).

Controlling for race, ethnicity, and the other confounders, women with less than a high school education or a high school diploma had similar likelihoods of cesarean delivery. The likelihood of a cesarean delivery was slightly reduced for women with a college degree (odds ratio, 0.93) or advanced degree (OR, 0.88). But this protective effect did not dampen racial/ethnic disparities. In fact, even greater disparities were seen at higher levels of education.

“At each level of education, all the racial/ethnic groups had significantly higher odds of a cesarean delivery than White women,” Dr. Eliner said. “Additionally, the racial/ethnic disparity in cesarean delivery rates increased with increasing level of education, and we specifically see a meaningful jump in the odds ratio at the college graduate level.”

She pointed out that the OR for cesarean delivery in Black women was 1.4 times greater than White women in the group with less than a high school education and 1.44 times greater in those with high school diplomas. Then it jumped to 1.69 in the college graduates group and 1.7 in the advanced degree group.

Higher maternal education was associated with a lower likelihood of cesarean delivery in White women and Asian women. White women with advanced degrees were 17% less likely to have a cesarean than White women with less than a high school education, and the respective reduction in risk was 19% for Asian women.

In Black women, however, education has a much smaller protective effect: An advanced degree reduced the odds of a cesarean delivery by only 7% and no significant difference showed up between high school graduates and college graduates, Dr. Eliner reported.

In Hispanic women, no protective effect showed up, and the odds of a cesarean delivery actually increased slightly in high school and college graduates above those with less than a high school education.

Dr. Eliner discussed a couple possible reasons for a less protective effect from maternal education in Black and Hispanic groups, including higher levels of chronic stress found in past research among racial/ethnic minorities with higher levels of education.

“The impact of racism as a chronic stressor and its association with adverse obstetric and prenatal outcomes is an emerging theme in health disparity research and is yet to be fully understood,” Dr. Eliner said in an interview. “Nonetheless, there is some evidence suggesting that racial/ethnic minorities with higher levels of education suffer from higher levels of stress.”

Implicit and explicit interpersonal bias and institutional racism may also play a role in the disparities, she said, and these factors may disproportionately affect the quality of care for more educated women. She also suggested that White women may be more comfortable advocating for their care.

“While less educated women from all racial/ethnic groups may lack the self-advocacy skills to discuss their labor course, educated White women may be more confident than women from educated minority groups,” Dr. Eliner told attendees. “They may therefore be better equipped to discuss the need for a cesarean delivery with their provider.”

Dr. Eliner elaborated on this: “Given the historical and current disparities of the health care system, women in racial/ethnic minorities may potentially be guarded in their interaction with medical professionals, with a reduced trust in the health care system, and may thus not feel empowered to advocate for themselves in this setting,” she said.

Allison Bryant Mantha, MD, MPH, vice chair for quality, equity, and safety in the ob.gyn. department at Massachusetts General Hospital, Boston, suggested that bias and racism may play a role in this self-advocacy as well.

“I’m wondering if it might not be equally plausible that the advocacy might be met differently by who’s delivering the message,” Dr. Bryant Mantha said. “I think from the story of Dr. Susan Moore and patients who advocate for themselves, I think that we know there is probably some differential by who’s delivering the message.”

Finally, even though education is usually highly correlated with income and frequently used as a proxy for it, but the effect of education on income varies by race/ethnicity.

Since education alone is not sufficient to reduce these disparities, potential interventions should focus on increasing awareness of the disparities and the role of implicit bias, improving patients’ trust in the medical system, and training more doctors from underrepresented groups, Dr. Eliner said.

“I was also wondering about the overall patient choice,” said Sarahn M. Wheeler, MD, an assistant professor of ob.gyn. at Duke University Medical Center in Durham, N.C., who comoderated the session with Dr. Bryant Mantha. “Did we have any understanding of differences in patient values systems that might go into some of these differences in findings as well? There are lots of interesting concepts to explore and that this abstract brings up.”

Dr. Eliner, Dr. Wheeler, and Dr. Bryant Mantha had no disclosures.
 

While the likelihood of a cesarean delivery usually drops as maternal education level increases, the disparities seen in cesarean rates between White and Black or Hispanic women actually increase with more maternal education, according to findings from a new study presented at the Pregnancy Meeting sponsored by the Society for Maternal-Fetal Medicine.

Typically, higher maternal education is associated with a lower likelihood of cesarean delivery, but this protective effect is much smaller for Black women and nonexistent for Hispanic women, leading to bigger gaps between these groups and White women, found Yael Eliner, MD, an ob.gyn. residency applicant at Boston University who conducted this research with her colleagues in the ob.gyn. department at Lenox Hill Hospital, New York, and Hofstra University, Hempstead, N.Y..

Researchers have previously identified racial and ethnic disparities in a wide range of maternal outcomes, including mortality, overall morbidity, preterm birth, low birth weight, fetal growth restriction, hypertensive disorders of pregnancy, diabetes, and cesarean deliveries. But the researchers wanted to know if the usual protective effects seen for cesarean deliveries existed in the racial and ethnic groups with these disparities. Past studies have already found that the protective effect of maternal education is greater for White women than Black women with infant mortality and overall self-rated health.

The researchers conducted a retrospective analysis of all low-risk nulliparous, term, singleton, vertex live births to U.S. residents from 2016 to 2019 by using the natality database of the Centers for Disease Control and Prevention. They looked only at women who were non-Hispanic White, non-Hispanic Black, non-Hispanic Asian, and Hispanic women. They excluded women with pregestational and gestational diabetes, chronic hypertension, and hypertensive disorders of pregnancy.

Maternal education levels were stratified into those without a high school diploma, high school graduates (including those with some college credit), college graduates, and those with advanced degrees. The total population included 2,969,207 mothers with a 23.4% cesarean delivery rate.

Before considering education or other potential confounders, the cesarean delivery rate was 27.4% in Black women and 25.6% in Asian women, compared with 22.4% in White women and 23% in Hispanic women (P < .001).

Among those with less than a high school education, Black (20.9%), Asian (23.1%), and Hispanic (17.9% cesarean delivery prevalence was greater than that among White women (17.2%) (P < .001). The same was true among those with a high school education (with or without some college): 22% of White women in this group had cesarean deliveries compared with 26.3% of Black women, 26.3% of Asian women, and 22.5% of Hispanic women (P < .001).

At higher levels of education, the disparities not only persisted but actually increased.

The prevalence of cesarean deliveries was 23% in White college graduates, compared with 32.5% of Black college graduates, 26.3% of Asian college graduates, and 27.7% of Hispanic college graduates (P < .001). Similarly, in those with an advanced degree, the prevalence of cesarean deliveries in their population set was 23.6% of Whites, 36.3% of Blacks, 26.1% of Asians, and 30.1% of Hispanics (P < .001).

After adjusting for maternal education as well as age, prepregnancy body mass index, weight gain during pregnancy, insurance type, and neonatal birth weight, the researchers still found substantial disparities in cesarean delivery rates. Black women had 1.54 times greater odds of cesarean delivery than White women (P < .001). Similarly, the odds were 1.45 times greater for Asian women and 1.24 times greater for Hispanic women (P < .001).

Controlling for race, ethnicity, and the other confounders, women with less than a high school education or a high school diploma had similar likelihoods of cesarean delivery. The likelihood of a cesarean delivery was slightly reduced for women with a college degree (odds ratio, 0.93) or advanced degree (OR, 0.88). But this protective effect did not dampen racial/ethnic disparities. In fact, even greater disparities were seen at higher levels of education.

“At each level of education, all the racial/ethnic groups had significantly higher odds of a cesarean delivery than White women,” Dr. Eliner said. “Additionally, the racial/ethnic disparity in cesarean delivery rates increased with increasing level of education, and we specifically see a meaningful jump in the odds ratio at the college graduate level.”

She pointed out that the OR for cesarean delivery in Black women was 1.4 times greater than White women in the group with less than a high school education and 1.44 times greater in those with high school diplomas. Then it jumped to 1.69 in the college graduates group and 1.7 in the advanced degree group.

Higher maternal education was associated with a lower likelihood of cesarean delivery in White women and Asian women. White women with advanced degrees were 17% less likely to have a cesarean than White women with less than a high school education, and the respective reduction in risk was 19% for Asian women.

In Black women, however, education has a much smaller protective effect: An advanced degree reduced the odds of a cesarean delivery by only 7% and no significant difference showed up between high school graduates and college graduates, Dr. Eliner reported.

In Hispanic women, no protective effect showed up, and the odds of a cesarean delivery actually increased slightly in high school and college graduates above those with less than a high school education.

Dr. Eliner discussed a couple possible reasons for a less protective effect from maternal education in Black and Hispanic groups, including higher levels of chronic stress found in past research among racial/ethnic minorities with higher levels of education.

“The impact of racism as a chronic stressor and its association with adverse obstetric and prenatal outcomes is an emerging theme in health disparity research and is yet to be fully understood,” Dr. Eliner said in an interview. “Nonetheless, there is some evidence suggesting that racial/ethnic minorities with higher levels of education suffer from higher levels of stress.”

Implicit and explicit interpersonal bias and institutional racism may also play a role in the disparities, she said, and these factors may disproportionately affect the quality of care for more educated women. She also suggested that White women may be more comfortable advocating for their care.

“While less educated women from all racial/ethnic groups may lack the self-advocacy skills to discuss their labor course, educated White women may be more confident than women from educated minority groups,” Dr. Eliner told attendees. “They may therefore be better equipped to discuss the need for a cesarean delivery with their provider.”

Dr. Eliner elaborated on this: “Given the historical and current disparities of the health care system, women in racial/ethnic minorities may potentially be guarded in their interaction with medical professionals, with a reduced trust in the health care system, and may thus not feel empowered to advocate for themselves in this setting,” she said.

Allison Bryant Mantha, MD, MPH, vice chair for quality, equity, and safety in the ob.gyn. department at Massachusetts General Hospital, Boston, suggested that bias and racism may play a role in this self-advocacy as well.

“I’m wondering if it might not be equally plausible that the advocacy might be met differently by who’s delivering the message,” Dr. Bryant Mantha said. “I think from the story of Dr. Susan Moore and patients who advocate for themselves, I think that we know there is probably some differential by who’s delivering the message.”

Finally, even though education is usually highly correlated with income and frequently used as a proxy for it, but the effect of education on income varies by race/ethnicity.

Since education alone is not sufficient to reduce these disparities, potential interventions should focus on increasing awareness of the disparities and the role of implicit bias, improving patients’ trust in the medical system, and training more doctors from underrepresented groups, Dr. Eliner said.

“I was also wondering about the overall patient choice,” said Sarahn M. Wheeler, MD, an assistant professor of ob.gyn. at Duke University Medical Center in Durham, N.C., who comoderated the session with Dr. Bryant Mantha. “Did we have any understanding of differences in patient values systems that might go into some of these differences in findings as well? There are lots of interesting concepts to explore and that this abstract brings up.”

Dr. Eliner, Dr. Wheeler, and Dr. Bryant Mantha had no disclosures.
 

While the likelihood of a cesarean delivery usually drops as maternal education level increases, the disparities seen in cesarean rates between White and Black or Hispanic women actually increase with more maternal education, according to findings from a new study presented at the Pregnancy Meeting sponsored by the Society for Maternal-Fetal Medicine.

Typically, higher maternal education is associated with a lower likelihood of cesarean delivery, but this protective effect is much smaller for Black women and nonexistent for Hispanic women, leading to bigger gaps between these groups and White women, found Yael Eliner, MD, an ob.gyn. residency applicant at Boston University who conducted this research with her colleagues in the ob.gyn. department at Lenox Hill Hospital, New York, and Hofstra University, Hempstead, N.Y..

Researchers have previously identified racial and ethnic disparities in a wide range of maternal outcomes, including mortality, overall morbidity, preterm birth, low birth weight, fetal growth restriction, hypertensive disorders of pregnancy, diabetes, and cesarean deliveries. But the researchers wanted to know if the usual protective effects seen for cesarean deliveries existed in the racial and ethnic groups with these disparities. Past studies have already found that the protective effect of maternal education is greater for White women than Black women with infant mortality and overall self-rated health.

The researchers conducted a retrospective analysis of all low-risk nulliparous, term, singleton, vertex live births to U.S. residents from 2016 to 2019 by using the natality database of the Centers for Disease Control and Prevention. They looked only at women who were non-Hispanic White, non-Hispanic Black, non-Hispanic Asian, and Hispanic women. They excluded women with pregestational and gestational diabetes, chronic hypertension, and hypertensive disorders of pregnancy.

Maternal education levels were stratified into those without a high school diploma, high school graduates (including those with some college credit), college graduates, and those with advanced degrees. The total population included 2,969,207 mothers with a 23.4% cesarean delivery rate.

Before considering education or other potential confounders, the cesarean delivery rate was 27.4% in Black women and 25.6% in Asian women, compared with 22.4% in White women and 23% in Hispanic women (P < .001).

Among those with less than a high school education, Black (20.9%), Asian (23.1%), and Hispanic (17.9% cesarean delivery prevalence was greater than that among White women (17.2%) (P < .001). The same was true among those with a high school education (with or without some college): 22% of White women in this group had cesarean deliveries compared with 26.3% of Black women, 26.3% of Asian women, and 22.5% of Hispanic women (P < .001).

At higher levels of education, the disparities not only persisted but actually increased.

The prevalence of cesarean deliveries was 23% in White college graduates, compared with 32.5% of Black college graduates, 26.3% of Asian college graduates, and 27.7% of Hispanic college graduates (P < .001). Similarly, in those with an advanced degree, the prevalence of cesarean deliveries in their population set was 23.6% of Whites, 36.3% of Blacks, 26.1% of Asians, and 30.1% of Hispanics (P < .001).

After adjusting for maternal education as well as age, prepregnancy body mass index, weight gain during pregnancy, insurance type, and neonatal birth weight, the researchers still found substantial disparities in cesarean delivery rates. Black women had 1.54 times greater odds of cesarean delivery than White women (P < .001). Similarly, the odds were 1.45 times greater for Asian women and 1.24 times greater for Hispanic women (P < .001).

Controlling for race, ethnicity, and the other confounders, women with less than a high school education or a high school diploma had similar likelihoods of cesarean delivery. The likelihood of a cesarean delivery was slightly reduced for women with a college degree (odds ratio, 0.93) or advanced degree (OR, 0.88). But this protective effect did not dampen racial/ethnic disparities. In fact, even greater disparities were seen at higher levels of education.

“At each level of education, all the racial/ethnic groups had significantly higher odds of a cesarean delivery than White women,” Dr. Eliner said. “Additionally, the racial/ethnic disparity in cesarean delivery rates increased with increasing level of education, and we specifically see a meaningful jump in the odds ratio at the college graduate level.”

She pointed out that the OR for cesarean delivery in Black women was 1.4 times greater than White women in the group with less than a high school education and 1.44 times greater in those with high school diplomas. Then it jumped to 1.69 in the college graduates group and 1.7 in the advanced degree group.

Higher maternal education was associated with a lower likelihood of cesarean delivery in White women and Asian women. White women with advanced degrees were 17% less likely to have a cesarean than White women with less than a high school education, and the respective reduction in risk was 19% for Asian women.

In Black women, however, education has a much smaller protective effect: An advanced degree reduced the odds of a cesarean delivery by only 7% and no significant difference showed up between high school graduates and college graduates, Dr. Eliner reported.

In Hispanic women, no protective effect showed up, and the odds of a cesarean delivery actually increased slightly in high school and college graduates above those with less than a high school education.

Dr. Eliner discussed a couple possible reasons for a less protective effect from maternal education in Black and Hispanic groups, including higher levels of chronic stress found in past research among racial/ethnic minorities with higher levels of education.

“The impact of racism as a chronic stressor and its association with adverse obstetric and prenatal outcomes is an emerging theme in health disparity research and is yet to be fully understood,” Dr. Eliner said in an interview. “Nonetheless, there is some evidence suggesting that racial/ethnic minorities with higher levels of education suffer from higher levels of stress.”

Implicit and explicit interpersonal bias and institutional racism may also play a role in the disparities, she said, and these factors may disproportionately affect the quality of care for more educated women. She also suggested that White women may be more comfortable advocating for their care.

“While less educated women from all racial/ethnic groups may lack the self-advocacy skills to discuss their labor course, educated White women may be more confident than women from educated minority groups,” Dr. Eliner told attendees. “They may therefore be better equipped to discuss the need for a cesarean delivery with their provider.”

Dr. Eliner elaborated on this: “Given the historical and current disparities of the health care system, women in racial/ethnic minorities may potentially be guarded in their interaction with medical professionals, with a reduced trust in the health care system, and may thus not feel empowered to advocate for themselves in this setting,” she said.

Allison Bryant Mantha, MD, MPH, vice chair for quality, equity, and safety in the ob.gyn. department at Massachusetts General Hospital, Boston, suggested that bias and racism may play a role in this self-advocacy as well.

“I’m wondering if it might not be equally plausible that the advocacy might be met differently by who’s delivering the message,” Dr. Bryant Mantha said. “I think from the story of Dr. Susan Moore and patients who advocate for themselves, I think that we know there is probably some differential by who’s delivering the message.”

Finally, even though education is usually highly correlated with income and frequently used as a proxy for it, but the effect of education on income varies by race/ethnicity.

Since education alone is not sufficient to reduce these disparities, potential interventions should focus on increasing awareness of the disparities and the role of implicit bias, improving patients’ trust in the medical system, and training more doctors from underrepresented groups, Dr. Eliner said.

“I was also wondering about the overall patient choice,” said Sarahn M. Wheeler, MD, an assistant professor of ob.gyn. at Duke University Medical Center in Durham, N.C., who comoderated the session with Dr. Bryant Mantha. “Did we have any understanding of differences in patient values systems that might go into some of these differences in findings as well? There are lots of interesting concepts to explore and that this abstract brings up.”

Dr. Eliner, Dr. Wheeler, and Dr. Bryant Mantha had no disclosures.
 

The more complaints of excessive force by police reported by neighborhood residents, the more likely it is that Black pregnant people living in that neighborhood will deliver preterm, according to findings from a new study presented Jan. 28 at the virtual Society for Maternal-Fetal Medicine 2021 Annual Pregnancy Meeting.

“We know there are significant racial disparities in preterm birth which aren’t fully explained by traditional risk factors, like being older, having health problems like high blood pressure, or limited income,” Alexa Freedman, PhD, a postdoctoral fellow at NorthShore University HealthSystem and Northwestern University Institute for Policy Research, Evanston, Ill., told this news organization. “This has left many wondering if there are stressors unique to Black individuals that may be involved,” which has led to past research on the association of preterm birth with neighborhood segregation and historical “redlining” practices.

Black individuals have a substantially higher rate of preterm birth, compared with all other racial and ethnic groups in the US: 13.8% of Black infants born between 2016 and 2018 were preterm, compared with 11.6% among Native Americans – the next highest group – and 9.1% among White women.

“Studies have shown that psychosocial stress contributes to preterm birth disparities, potentially through several physiologic pathways that impact pregnancy outcomes,” Dr. Freedman told attendees. “Pregnant Black individuals have been reported to experience greater psychosocial stress regardless of socioeconomic status, possibly secondary to experiences of racism and discrimination.”

Though past research has examined neighborhood disadvantage and violence as stressors potentially contributing to preterm birth, little data exist on police–community relationships or police violence and pregnancy outcomes, despite being a “particularly salient stressor for Black individuals,” Dr. Freedman said. “Among pregnant Black individuals, prenatal depression has been correlated with concern about negative interactions between youth in their community and police.” To cite one example of the prevalence of racial bias in policing, she noted that “Chicago police are almost 10 times more likely to use force when interacting with a Black individual as compared [with] a White individual.”

The researchers therefore sought to determine whether a relationship existed between preterm birth rates and complaints regarding use of excessive force by police in the same neighborhood. They compiled records on all singleton live births from one Chicago hospital between March 2008 and March 2018, excluding those who lived outside Chicago, had a missing address, listed their race as “other,” or lacked data for specific other confounders.
 

Assessing police complaints within census blocks

The researchers obtained data on police complaints in Chicago from the Invisible Institute’s Citizen Police Data Project. They focused only on complaints of excessive use of force, “such as unnecessary physical contact and unnecessary display of a weapon,” Dr. Freedman said. They considered a person exposed in the neighborhood if a complaint was reported in her census block in the year leading up to birth. During their study period, more than 6,000 complaints of excessive force were reported across an estimated 70% of the blocks.

The study population had an average age of 31 and included 59.5% White, 12% Black, 20% Hispanic, and 8.5% Asian people. Just over half the pregnancies (55%) were first-time pregnancies, and 3.3% of the population had a history of preterm birth (before 37 weeks). The researchers also gathered data to adjust for the study population’s:

• Age
• Parity (number of times the woman has given birth).
• Population size of census block.
• Exposure to a homicide on the block in the year leading up to birth.
• Socioeconomic status by block (based on a composite of median home value, median income, percentage of a high school diploma, and percentage employed).

“Those who lived in a block with an excessive force complaint were more likely to be Black, more likely to deliver preterm, and more likely to be exposed to homicide,” Dr. Freedman told attendees.

The proportion of pregnant women exposed to police complaints was 15.8%, and 10.2% lived in neighborhoods where a homicide occurred in the year leading up to birth. Within the group exposed to a homicide, 16.5% lived in a neighborhood with an excessive force complaint and 9.1% did not.

Overall, 8.1% of the population gave birth preterm. When stratified by whether or not they lived in a block with an excessive force complaint, the researchers found the proportion of preterm births was higher among those who did than those who did not (9.3% vs. 7.8%).

Both before and after adjusting for confounders, Black people were the only racial/ethnic group who had a significantly increased risk of preterm birth if they lived on a block with a complaint. They were nearly 30% more likely to deliver preterm if an excessive force complaint had been reported nearby (odds ratio, 1.29). The odds of preterm birth were slightly elevated for White people and slightly reduced for Hispanic and Asian people, but none of those associations reached significance.

In a sensitivity analysis comparing 189 Black individuals to themselves, the researchers compared those who had one preterm birth and one term birth. They found that the preterm birth was 32% more likely to occur in a year when an excessive force complaint was filed after adjusting for age and birth order (OR, 1.32; 95% confidence interval, 0.82-2.13).

“Police violence reflects just one component of structural racism,” Dr. Freedman said in an interview. “Our findings highlight the need to more thoroughly consider how these systemic and structural factors contribute to disparities in maternal and fetal health.”
 

Clinical and policy implications

The clinical implications of these findings focus on the need for obstetric clinical teams to understand patients’ stressors and to provide support and resources, according to Dr. Freedman’s mentor, Ann Borders, MD, MSc, MPH, a maternal-fetal medicine physician at NorthShore and Evanston Hospital and a clinical associate professor at the University of Chicago Pritzker School of Medicine.

“Potential strategies include training on improved listening and respectful patient-centered care, such as provided by the CDC Hear Her campaign, and consideration of universal social determinants of health screening during obstetric care,” Dr. Borders told this news organization..

Though the study included a large sample size and allowed the researchers to control for individual and neighborhood characteristics, Dr. Freedman acknowledged that census blocks may or may not correlate with the way individuals define their own neighborhoods. They also didn’t have the data to assess the quality of prenatal care or the type of preterm birth, but they are developing a qualitative study to determine the best ways of measuring exposure to police violence.

In addition, the researchers’ reliance only on formal police complaints could have underestimated prevalence of excessive force, and the study did not take into account people’s direct experience with police violence; police violence that occurs within a person’s social network; or police violence widely covered in the news. 

It wasn’t possible for the researchers to verify whether excessive force actually occurred or whether the force might have been justified, and it instead relied on the fact that someone lodged a complaint because he or she perceived the action as excessive.

Allison Bryant Mantha, MD, MPH, vice chair for Quality, Equity, and Safety at Massachusetts General Hospital in Boston and a board member of SMFM, said she was impressed with the adjustment of homicide exposure as a proxy for neighborhood crime.

“Many might assume that reports of police misconduct might be a marker for a ‘dangerous neighborhood,’ and it was thoughtful of the authors to adjust their analyses for exposure to crime to demonstrate that, even above and beyond crime, reports of police misconduct seem to be associated with adverse outcomes,” Dr. Bryant Mantha, who moderated the session, said in an interview.

Confronting this issue goes beyond what clinicians can do on their own, Dr. Bryant Mantha suggested.

“The greatest change will come with addressing the structural racism that underlies differential exposure to police misconduct in communities in the first place,” she said. “Concurrent with this, however, clinicians may consider adding in an assessment of neighborhood characteristics to include reports of police misconduct as they screen for other social determinants of health. While we do not have intervention studies to demonstrate efficacy, it is not a huge leap to imagine that recognition of this burden in individuals’ lives, plus offering ways to manage stress or seek redress, could be of benefit.”

The research was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Institute on Minority Health and Health Disparities, and the Northwestern Medicine Enterprise Data Warehouse Pilot Data Program. Dr. Freedman, Dr. Borders, and Dr. Bryant Mantha have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

The more complaints of excessive force by police reported by neighborhood residents, the more likely it is that Black pregnant people living in that neighborhood will deliver preterm, according to findings from a new study presented Jan. 28 at the virtual Society for Maternal-Fetal Medicine 2021 Annual Pregnancy Meeting.

“We know there are significant racial disparities in preterm birth which aren’t fully explained by traditional risk factors, like being older, having health problems like high blood pressure, or limited income,” Alexa Freedman, PhD, a postdoctoral fellow at NorthShore University HealthSystem and Northwestern University Institute for Policy Research, Evanston, Ill., told this news organization. “This has left many wondering if there are stressors unique to Black individuals that may be involved,” which has led to past research on the association of preterm birth with neighborhood segregation and historical “redlining” practices.

Black individuals have a substantially higher rate of preterm birth, compared with all other racial and ethnic groups in the US: 13.8% of Black infants born between 2016 and 2018 were preterm, compared with 11.6% among Native Americans – the next highest group – and 9.1% among White women.

“Studies have shown that psychosocial stress contributes to preterm birth disparities, potentially through several physiologic pathways that impact pregnancy outcomes,” Dr. Freedman told attendees. “Pregnant Black individuals have been reported to experience greater psychosocial stress regardless of socioeconomic status, possibly secondary to experiences of racism and discrimination.”

Though past research has examined neighborhood disadvantage and violence as stressors potentially contributing to preterm birth, little data exist on police–community relationships or police violence and pregnancy outcomes, despite being a “particularly salient stressor for Black individuals,” Dr. Freedman said. “Among pregnant Black individuals, prenatal depression has been correlated with concern about negative interactions between youth in their community and police.” To cite one example of the prevalence of racial bias in policing, she noted that “Chicago police are almost 10 times more likely to use force when interacting with a Black individual as compared [with] a White individual.”

The researchers therefore sought to determine whether a relationship existed between preterm birth rates and complaints regarding use of excessive force by police in the same neighborhood. They compiled records on all singleton live births from one Chicago hospital between March 2008 and March 2018, excluding those who lived outside Chicago, had a missing address, listed their race as “other,” or lacked data for specific other confounders.
 

Assessing police complaints within census blocks

The researchers obtained data on police complaints in Chicago from the Invisible Institute’s Citizen Police Data Project. They focused only on complaints of excessive use of force, “such as unnecessary physical contact and unnecessary display of a weapon,” Dr. Freedman said. They considered a person exposed in the neighborhood if a complaint was reported in her census block in the year leading up to birth. During their study period, more than 6,000 complaints of excessive force were reported across an estimated 70% of the blocks.

The study population had an average age of 31 and included 59.5% White, 12% Black, 20% Hispanic, and 8.5% Asian people. Just over half the pregnancies (55%) were first-time pregnancies, and 3.3% of the population had a history of preterm birth (before 37 weeks). The researchers also gathered data to adjust for the study population’s:

• Age
• Parity (number of times the woman has given birth).
• Population size of census block.
• Exposure to a homicide on the block in the year leading up to birth.
• Socioeconomic status by block (based on a composite of median home value, median income, percentage of a high school diploma, and percentage employed).

“Those who lived in a block with an excessive force complaint were more likely to be Black, more likely to deliver preterm, and more likely to be exposed to homicide,” Dr. Freedman told attendees.

The proportion of pregnant women exposed to police complaints was 15.8%, and 10.2% lived in neighborhoods where a homicide occurred in the year leading up to birth. Within the group exposed to a homicide, 16.5% lived in a neighborhood with an excessive force complaint and 9.1% did not.

Overall, 8.1% of the population gave birth preterm. When stratified by whether or not they lived in a block with an excessive force complaint, the researchers found the proportion of preterm births was higher among those who did than those who did not (9.3% vs. 7.8%).

Both before and after adjusting for confounders, Black people were the only racial/ethnic group who had a significantly increased risk of preterm birth if they lived on a block with a complaint. They were nearly 30% more likely to deliver preterm if an excessive force complaint had been reported nearby (odds ratio, 1.29). The odds of preterm birth were slightly elevated for White people and slightly reduced for Hispanic and Asian people, but none of those associations reached significance.

In a sensitivity analysis comparing 189 Black individuals to themselves, the researchers compared those who had one preterm birth and one term birth. They found that the preterm birth was 32% more likely to occur in a year when an excessive force complaint was filed after adjusting for age and birth order (OR, 1.32; 95% confidence interval, 0.82-2.13).

“Police violence reflects just one component of structural racism,” Dr. Freedman said in an interview. “Our findings highlight the need to more thoroughly consider how these systemic and structural factors contribute to disparities in maternal and fetal health.”
 

Clinical and policy implications

The clinical implications of these findings focus on the need for obstetric clinical teams to understand patients’ stressors and to provide support and resources, according to Dr. Freedman’s mentor, Ann Borders, MD, MSc, MPH, a maternal-fetal medicine physician at NorthShore and Evanston Hospital and a clinical associate professor at the University of Chicago Pritzker School of Medicine.

“Potential strategies include training on improved listening and respectful patient-centered care, such as provided by the CDC Hear Her campaign, and consideration of universal social determinants of health screening during obstetric care,” Dr. Borders told this news organization..

Though the study included a large sample size and allowed the researchers to control for individual and neighborhood characteristics, Dr. Freedman acknowledged that census blocks may or may not correlate with the way individuals define their own neighborhoods. They also didn’t have the data to assess the quality of prenatal care or the type of preterm birth, but they are developing a qualitative study to determine the best ways of measuring exposure to police violence.

In addition, the researchers’ reliance only on formal police complaints could have underestimated prevalence of excessive force, and the study did not take into account people’s direct experience with police violence; police violence that occurs within a person’s social network; or police violence widely covered in the news. 

It wasn’t possible for the researchers to verify whether excessive force actually occurred or whether the force might have been justified, and it instead relied on the fact that someone lodged a complaint because he or she perceived the action as excessive.

Allison Bryant Mantha, MD, MPH, vice chair for Quality, Equity, and Safety at Massachusetts General Hospital in Boston and a board member of SMFM, said she was impressed with the adjustment of homicide exposure as a proxy for neighborhood crime.

“Many might assume that reports of police misconduct might be a marker for a ‘dangerous neighborhood,’ and it was thoughtful of the authors to adjust their analyses for exposure to crime to demonstrate that, even above and beyond crime, reports of police misconduct seem to be associated with adverse outcomes,” Dr. Bryant Mantha, who moderated the session, said in an interview.

Confronting this issue goes beyond what clinicians can do on their own, Dr. Bryant Mantha suggested.

“The greatest change will come with addressing the structural racism that underlies differential exposure to police misconduct in communities in the first place,” she said. “Concurrent with this, however, clinicians may consider adding in an assessment of neighborhood characteristics to include reports of police misconduct as they screen for other social determinants of health. While we do not have intervention studies to demonstrate efficacy, it is not a huge leap to imagine that recognition of this burden in individuals’ lives, plus offering ways to manage stress or seek redress, could be of benefit.”

The research was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Institute on Minority Health and Health Disparities, and the Northwestern Medicine Enterprise Data Warehouse Pilot Data Program. Dr. Freedman, Dr. Borders, and Dr. Bryant Mantha have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

The more complaints of excessive force by police reported by neighborhood residents, the more likely it is that Black pregnant people living in that neighborhood will deliver preterm, according to findings from a new study presented Jan. 28 at the virtual Society for Maternal-Fetal Medicine 2021 Annual Pregnancy Meeting.

“We know there are significant racial disparities in preterm birth which aren’t fully explained by traditional risk factors, like being older, having health problems like high blood pressure, or limited income,” Alexa Freedman, PhD, a postdoctoral fellow at NorthShore University HealthSystem and Northwestern University Institute for Policy Research, Evanston, Ill., told this news organization. “This has left many wondering if there are stressors unique to Black individuals that may be involved,” which has led to past research on the association of preterm birth with neighborhood segregation and historical “redlining” practices.

Black individuals have a substantially higher rate of preterm birth, compared with all other racial and ethnic groups in the US: 13.8% of Black infants born between 2016 and 2018 were preterm, compared with 11.6% among Native Americans – the next highest group – and 9.1% among White women.

“Studies have shown that psychosocial stress contributes to preterm birth disparities, potentially through several physiologic pathways that impact pregnancy outcomes,” Dr. Freedman told attendees. “Pregnant Black individuals have been reported to experience greater psychosocial stress regardless of socioeconomic status, possibly secondary to experiences of racism and discrimination.”

Though past research has examined neighborhood disadvantage and violence as stressors potentially contributing to preterm birth, little data exist on police–community relationships or police violence and pregnancy outcomes, despite being a “particularly salient stressor for Black individuals,” Dr. Freedman said. “Among pregnant Black individuals, prenatal depression has been correlated with concern about negative interactions between youth in their community and police.” To cite one example of the prevalence of racial bias in policing, she noted that “Chicago police are almost 10 times more likely to use force when interacting with a Black individual as compared [with] a White individual.”

The researchers therefore sought to determine whether a relationship existed between preterm birth rates and complaints regarding use of excessive force by police in the same neighborhood. They compiled records on all singleton live births from one Chicago hospital between March 2008 and March 2018, excluding those who lived outside Chicago, had a missing address, listed their race as “other,” or lacked data for specific other confounders.
 

Assessing police complaints within census blocks

The researchers obtained data on police complaints in Chicago from the Invisible Institute’s Citizen Police Data Project. They focused only on complaints of excessive use of force, “such as unnecessary physical contact and unnecessary display of a weapon,” Dr. Freedman said. They considered a person exposed in the neighborhood if a complaint was reported in her census block in the year leading up to birth. During their study period, more than 6,000 complaints of excessive force were reported across an estimated 70% of the blocks.

The study population had an average age of 31 and included 59.5% White, 12% Black, 20% Hispanic, and 8.5% Asian people. Just over half the pregnancies (55%) were first-time pregnancies, and 3.3% of the population had a history of preterm birth (before 37 weeks). The researchers also gathered data to adjust for the study population’s:

• Age
• Parity (number of times the woman has given birth).
• Population size of census block.
• Exposure to a homicide on the block in the year leading up to birth.
• Socioeconomic status by block (based on a composite of median home value, median income, percentage of a high school diploma, and percentage employed).

“Those who lived in a block with an excessive force complaint were more likely to be Black, more likely to deliver preterm, and more likely to be exposed to homicide,” Dr. Freedman told attendees.

The proportion of pregnant women exposed to police complaints was 15.8%, and 10.2% lived in neighborhoods where a homicide occurred in the year leading up to birth. Within the group exposed to a homicide, 16.5% lived in a neighborhood with an excessive force complaint and 9.1% did not.

Overall, 8.1% of the population gave birth preterm. When stratified by whether or not they lived in a block with an excessive force complaint, the researchers found the proportion of preterm births was higher among those who did than those who did not (9.3% vs. 7.8%).

Both before and after adjusting for confounders, Black people were the only racial/ethnic group who had a significantly increased risk of preterm birth if they lived on a block with a complaint. They were nearly 30% more likely to deliver preterm if an excessive force complaint had been reported nearby (odds ratio, 1.29). The odds of preterm birth were slightly elevated for White people and slightly reduced for Hispanic and Asian people, but none of those associations reached significance.

In a sensitivity analysis comparing 189 Black individuals to themselves, the researchers compared those who had one preterm birth and one term birth. They found that the preterm birth was 32% more likely to occur in a year when an excessive force complaint was filed after adjusting for age and birth order (OR, 1.32; 95% confidence interval, 0.82-2.13).

“Police violence reflects just one component of structural racism,” Dr. Freedman said in an interview. “Our findings highlight the need to more thoroughly consider how these systemic and structural factors contribute to disparities in maternal and fetal health.”
 

Clinical and policy implications

The clinical implications of these findings focus on the need for obstetric clinical teams to understand patients’ stressors and to provide support and resources, according to Dr. Freedman’s mentor, Ann Borders, MD, MSc, MPH, a maternal-fetal medicine physician at NorthShore and Evanston Hospital and a clinical associate professor at the University of Chicago Pritzker School of Medicine.

“Potential strategies include training on improved listening and respectful patient-centered care, such as provided by the CDC Hear Her campaign, and consideration of universal social determinants of health screening during obstetric care,” Dr. Borders told this news organization..

Though the study included a large sample size and allowed the researchers to control for individual and neighborhood characteristics, Dr. Freedman acknowledged that census blocks may or may not correlate with the way individuals define their own neighborhoods. They also didn’t have the data to assess the quality of prenatal care or the type of preterm birth, but they are developing a qualitative study to determine the best ways of measuring exposure to police violence.

In addition, the researchers’ reliance only on formal police complaints could have underestimated prevalence of excessive force, and the study did not take into account people’s direct experience with police violence; police violence that occurs within a person’s social network; or police violence widely covered in the news. 

It wasn’t possible for the researchers to verify whether excessive force actually occurred or whether the force might have been justified, and it instead relied on the fact that someone lodged a complaint because he or she perceived the action as excessive.

Allison Bryant Mantha, MD, MPH, vice chair for Quality, Equity, and Safety at Massachusetts General Hospital in Boston and a board member of SMFM, said she was impressed with the adjustment of homicide exposure as a proxy for neighborhood crime.

“Many might assume that reports of police misconduct might be a marker for a ‘dangerous neighborhood,’ and it was thoughtful of the authors to adjust their analyses for exposure to crime to demonstrate that, even above and beyond crime, reports of police misconduct seem to be associated with adverse outcomes,” Dr. Bryant Mantha, who moderated the session, said in an interview.

Confronting this issue goes beyond what clinicians can do on their own, Dr. Bryant Mantha suggested.

“The greatest change will come with addressing the structural racism that underlies differential exposure to police misconduct in communities in the first place,” she said. “Concurrent with this, however, clinicians may consider adding in an assessment of neighborhood characteristics to include reports of police misconduct as they screen for other social determinants of health. While we do not have intervention studies to demonstrate efficacy, it is not a huge leap to imagine that recognition of this burden in individuals’ lives, plus offering ways to manage stress or seek redress, could be of benefit.”

The research was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Institute on Minority Health and Health Disparities, and the Northwestern Medicine Enterprise Data Warehouse Pilot Data Program. Dr. Freedman, Dr. Borders, and Dr. Bryant Mantha have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

An analysis of data from the U.S. military suggests that the maternal morbidity disparities between Black and White women cannot be attributed solely to differences in access to care and socioeconomics.

Even in the U.S. military health care system, where all service members have universal access to the same facilities and providers, researchers found substantial racial disparities in cesarean deliveries, maternal ICU admission, and overall severe maternal morbidity and mortality between Black patients and White patients, according to findings from a new study presented Jan. 28, 2021, at a meeting sponsored by the Society for Maternal-Fetal Medicine.

“This was surprising given some of the driving theories behind maternal race disparities encountered in this country, such as access to care and socioeconomic status, are controlled for in this health care system,” Capt. Jameaka Hamilton, MD, who presented the research, said in an interview. “Our findings indicate that there are likely additional factors at play which impact the obstetrical outcomes of women based upon their race, including systems-based barriers to accessing the military health care system which contribute to health care disparities, or in systemic or implicit biases which occur within our health care delivery.”

Plenty of recent research has documented the rise in maternal morbidity and mortality in the United States and the considerable racial disparities within those statistics. Black women are twice as likely to suffer morbidity and three to four times more likely to die in childbirth, compared with White women, Dr. Hamilton, an ob.gyn. from the San Antonio Uniformed Services Health Education Consortium at Ft. Sam Houston in San Antonio, Texas, reminded attendees. So far, much of this disparity has been attributed to social determinants of health.

Military retirees, active-duty personnel, and dependents, however, have equal access to federal health insurance and care at military health care facilities, or at covered civilian facilities where needed. Hence the researchers’ hypothesis that the military medical system would not show the same disparities by race that are seen in civilian populations.

The researchers analyzed maternal morbidity data from the Neonatal Perinatal Information Center from April 2018 to March 2019. The retrospective study included data from 13 military treatment facilities that had more than 1,000 deliveries per year. In addition to statistics on cesarean delivery and adult ICU admission, the researchers compared numbers on overall severe maternal morbidity based on the indicators defined by the Centers for Disease Control and Prevention.

The 15,305 deliveries included 23% Black patients and 77% White patients from the Air Force, Army, and Navy branches.

The cesarean delivery rate ranged from 19.4% to 35.5%. ICU admissions totaled 38 women, 190 women had postpartum hemorrhage, and 282 women experienced severe maternal morbidity. All three measures revealed racial disparities:

• Overall severe maternal morbidity occurred in 2.66% of Black women and 1.66% of White women (P =.0001).
• ICU admission occurred in 0.49% of Black women and 0.18% of White women (P =.0026).
• 31.68% of Black women had a cesarean delivery, compared with 23.58% of White women (P <.0001).

After excluding cases with blood transfusions, Black women were twice as likely to have severe maternal morbidity (0.64% vs. 0.32%). There were no significant differences in postpartum hemorrhage rates between Black and White women, but this analysis was limited by the small overall numbers of postpartum hemorrhage.

Among the study’s limitations were the inability to stratify patients by retiree, active duty, or dependent status, and the lack of data on preeclampsia rates, maternal age, obesity, or other preexisting conditions. In addition, the initial dataset included 61% of patients who reported their race as “other” than Black or White, limiting the number of patients whose data could be analyzed. Since low-volume hospitals were excluded, the outcomes could be skewed if lower-volume facilities are more likely to care for more complex cases, Dr. Hamilton added.

Allison Bryant Mantha, MD, MPH, vice chair for quality, equity, and safety in the ob.gyn. department at Massachusetts General Hospital, Boston, praised Dr. Hamilton’s work for revealing that differential access – though still problematic – cannot fully explain inequities between Black women and other women.

“The findings are not shocking given that what underlies some of these inequities – namely structural and institutional racism, and differential treatment within the system – are not exclusive to civilian health care settings,” Dr. Bryant Mantha, who moderated the session, said in an interview. “That said, doing the work to demonstrate this is extremely valuable.”

Although the causes of these disparities are systemic, Dr. Hamilton said individual providers can play a role in addressing them.

“There can certainly be more done to address this dangerous trend at the provider, hospital/institution, and national level,” she said. I think we as providers should continue to self-reflect and address our own biases. Hospitals and institutions should continue to develop policies that draw attention health care disparities.”

Completely removing these inequalities, however, will require confronting the racism embedded in U.S. health care at all levels, Dr. Bryant Mantha suggested.

“Ultimately, moving to an antiracist health care system – and criminal justice system, educational system, political system, etc. – and dismantling the existing structural racism in policies and practices will be needed to drive this change,” Dr. Bryant Mantha said. “Individual clinicians can use their voices to advocate for these changes in their health systems, communities, and states. Awareness of these inequities is critical, as is a sense of collective efficacy that we can, indeed, change the status quo.”

Dr. Hamilton and Dr. Bryant Mantha reported no disclosures.

An analysis of data from the U.S. military suggests that the maternal morbidity disparities between Black and White women cannot be attributed solely to differences in access to care and socioeconomics.

Even in the U.S. military health care system, where all service members have universal access to the same facilities and providers, researchers found substantial racial disparities in cesarean deliveries, maternal ICU admission, and overall severe maternal morbidity and mortality between Black patients and White patients, according to findings from a new study presented Jan. 28, 2021, at a meeting sponsored by the Society for Maternal-Fetal Medicine.

“This was surprising given some of the driving theories behind maternal race disparities encountered in this country, such as access to care and socioeconomic status, are controlled for in this health care system,” Capt. Jameaka Hamilton, MD, who presented the research, said in an interview. “Our findings indicate that there are likely additional factors at play which impact the obstetrical outcomes of women based upon their race, including systems-based barriers to accessing the military health care system which contribute to health care disparities, or in systemic or implicit biases which occur within our health care delivery.”

Plenty of recent research has documented the rise in maternal morbidity and mortality in the United States and the considerable racial disparities within those statistics. Black women are twice as likely to suffer morbidity and three to four times more likely to die in childbirth, compared with White women, Dr. Hamilton, an ob.gyn. from the San Antonio Uniformed Services Health Education Consortium at Ft. Sam Houston in San Antonio, Texas, reminded attendees. So far, much of this disparity has been attributed to social determinants of health.

Military retirees, active-duty personnel, and dependents, however, have equal access to federal health insurance and care at military health care facilities, or at covered civilian facilities where needed. Hence the researchers’ hypothesis that the military medical system would not show the same disparities by race that are seen in civilian populations.

The researchers analyzed maternal morbidity data from the Neonatal Perinatal Information Center from April 2018 to March 2019. The retrospective study included data from 13 military treatment facilities that had more than 1,000 deliveries per year. In addition to statistics on cesarean delivery and adult ICU admission, the researchers compared numbers on overall severe maternal morbidity based on the indicators defined by the Centers for Disease Control and Prevention.

The 15,305 deliveries included 23% Black patients and 77% White patients from the Air Force, Army, and Navy branches.

The cesarean delivery rate ranged from 19.4% to 35.5%. ICU admissions totaled 38 women, 190 women had postpartum hemorrhage, and 282 women experienced severe maternal morbidity. All three measures revealed racial disparities:

• Overall severe maternal morbidity occurred in 2.66% of Black women and 1.66% of White women (P =.0001).
• ICU admission occurred in 0.49% of Black women and 0.18% of White women (P =.0026).
• 31.68% of Black women had a cesarean delivery, compared with 23.58% of White women (P <.0001).

After excluding cases with blood transfusions, Black women were twice as likely to have severe maternal morbidity (0.64% vs. 0.32%). There were no significant differences in postpartum hemorrhage rates between Black and White women, but this analysis was limited by the small overall numbers of postpartum hemorrhage.

Among the study’s limitations were the inability to stratify patients by retiree, active duty, or dependent status, and the lack of data on preeclampsia rates, maternal age, obesity, or other preexisting conditions. In addition, the initial dataset included 61% of patients who reported their race as “other” than Black or White, limiting the number of patients whose data could be analyzed. Since low-volume hospitals were excluded, the outcomes could be skewed if lower-volume facilities are more likely to care for more complex cases, Dr. Hamilton added.

Allison Bryant Mantha, MD, MPH, vice chair for quality, equity, and safety in the ob.gyn. department at Massachusetts General Hospital, Boston, praised Dr. Hamilton’s work for revealing that differential access – though still problematic – cannot fully explain inequities between Black women and other women.

“The findings are not shocking given that what underlies some of these inequities – namely structural and institutional racism, and differential treatment within the system – are not exclusive to civilian health care settings,” Dr. Bryant Mantha, who moderated the session, said in an interview. “That said, doing the work to demonstrate this is extremely valuable.”

Although the causes of these disparities are systemic, Dr. Hamilton said individual providers can play a role in addressing them.

“There can certainly be more done to address this dangerous trend at the provider, hospital/institution, and national level,” she said. I think we as providers should continue to self-reflect and address our own biases. Hospitals and institutions should continue to develop policies that draw attention health care disparities.”

Completely removing these inequalities, however, will require confronting the racism embedded in U.S. health care at all levels, Dr. Bryant Mantha suggested.

“Ultimately, moving to an antiracist health care system – and criminal justice system, educational system, political system, etc. – and dismantling the existing structural racism in policies and practices will be needed to drive this change,” Dr. Bryant Mantha said. “Individual clinicians can use their voices to advocate for these changes in their health systems, communities, and states. Awareness of these inequities is critical, as is a sense of collective efficacy that we can, indeed, change the status quo.”

Dr. Hamilton and Dr. Bryant Mantha reported no disclosures.

An analysis of data from the U.S. military suggests that the maternal morbidity disparities between Black and White women cannot be attributed solely to differences in access to care and socioeconomics.

Even in the U.S. military health care system, where all service members have universal access to the same facilities and providers, researchers found substantial racial disparities in cesarean deliveries, maternal ICU admission, and overall severe maternal morbidity and mortality between Black patients and White patients, according to findings from a new study presented Jan. 28, 2021, at a meeting sponsored by the Society for Maternal-Fetal Medicine.

“This was surprising given some of the driving theories behind maternal race disparities encountered in this country, such as access to care and socioeconomic status, are controlled for in this health care system,” Capt. Jameaka Hamilton, MD, who presented the research, said in an interview. “Our findings indicate that there are likely additional factors at play which impact the obstetrical outcomes of women based upon their race, including systems-based barriers to accessing the military health care system which contribute to health care disparities, or in systemic or implicit biases which occur within our health care delivery.”

Plenty of recent research has documented the rise in maternal morbidity and mortality in the United States and the considerable racial disparities within those statistics. Black women are twice as likely to suffer morbidity and three to four times more likely to die in childbirth, compared with White women, Dr. Hamilton, an ob.gyn. from the San Antonio Uniformed Services Health Education Consortium at Ft. Sam Houston in San Antonio, Texas, reminded attendees. So far, much of this disparity has been attributed to social determinants of health.

Military retirees, active-duty personnel, and dependents, however, have equal access to federal health insurance and care at military health care facilities, or at covered civilian facilities where needed. Hence the researchers’ hypothesis that the military medical system would not show the same disparities by race that are seen in civilian populations.

The researchers analyzed maternal morbidity data from the Neonatal Perinatal Information Center from April 2018 to March 2019. The retrospective study included data from 13 military treatment facilities that had more than 1,000 deliveries per year. In addition to statistics on cesarean delivery and adult ICU admission, the researchers compared numbers on overall severe maternal morbidity based on the indicators defined by the Centers for Disease Control and Prevention.

The 15,305 deliveries included 23% Black patients and 77% White patients from the Air Force, Army, and Navy branches.

The cesarean delivery rate ranged from 19.4% to 35.5%. ICU admissions totaled 38 women, 190 women had postpartum hemorrhage, and 282 women experienced severe maternal morbidity. All three measures revealed racial disparities:

• Overall severe maternal morbidity occurred in 2.66% of Black women and 1.66% of White women (P =.0001).
• ICU admission occurred in 0.49% of Black women and 0.18% of White women (P =.0026).
• 31.68% of Black women had a cesarean delivery, compared with 23.58% of White women (P <.0001).

After excluding cases with blood transfusions, Black women were twice as likely to have severe maternal morbidity (0.64% vs. 0.32%). There were no significant differences in postpartum hemorrhage rates between Black and White women, but this analysis was limited by the small overall numbers of postpartum hemorrhage.

Among the study’s limitations were the inability to stratify patients by retiree, active duty, or dependent status, and the lack of data on preeclampsia rates, maternal age, obesity, or other preexisting conditions. In addition, the initial dataset included 61% of patients who reported their race as “other” than Black or White, limiting the number of patients whose data could be analyzed. Since low-volume hospitals were excluded, the outcomes could be skewed if lower-volume facilities are more likely to care for more complex cases, Dr. Hamilton added.

Allison Bryant Mantha, MD, MPH, vice chair for quality, equity, and safety in the ob.gyn. department at Massachusetts General Hospital, Boston, praised Dr. Hamilton’s work for revealing that differential access – though still problematic – cannot fully explain inequities between Black women and other women.

“The findings are not shocking given that what underlies some of these inequities – namely structural and institutional racism, and differential treatment within the system – are not exclusive to civilian health care settings,” Dr. Bryant Mantha, who moderated the session, said in an interview. “That said, doing the work to demonstrate this is extremely valuable.”

Although the causes of these disparities are systemic, Dr. Hamilton said individual providers can play a role in addressing them.

“There can certainly be more done to address this dangerous trend at the provider, hospital/institution, and national level,” she said. I think we as providers should continue to self-reflect and address our own biases. Hospitals and institutions should continue to develop policies that draw attention health care disparities.”

Completely removing these inequalities, however, will require confronting the racism embedded in U.S. health care at all levels, Dr. Bryant Mantha suggested.

“Ultimately, moving to an antiracist health care system – and criminal justice system, educational system, political system, etc. – and dismantling the existing structural racism in policies and practices will be needed to drive this change,” Dr. Bryant Mantha said. “Individual clinicians can use their voices to advocate for these changes in their health systems, communities, and states. Awareness of these inequities is critical, as is a sense of collective efficacy that we can, indeed, change the status quo.”

Dr. Hamilton and Dr. Bryant Mantha reported no disclosures.

Women at risk of preterm birth who took daily low-dose aspirin did not have significantly lower rates of preterm birth than those who did not take aspirin, according to preliminary findings from a small randomized controlled trial. There was a trend toward lower rates, especially among those with the highest compliance, but the study was underpowered to detect a difference with statistical significance, said Anadeijda Landman, MD, of the Amsterdam University Medical Center. Dr. Landman presented the findings Jan. 28 at a meeting sponsored by the Society for Maternal-Fetal Medicine.

Preterm birth accounts for a third of all neonatal mortality, she told attendees. Among 15 million preterm births worldwide each year, 65% are spontaneous, indicating the need for effective preventive interventions. Dr. Landman reviewed several mechanisms by which aspirin may help reduce preterm birth via different pathways.

The researchers’ multicenter, placebo-controlled trial involved 8 tertiary care and 26 secondary care hospitals in the Netherlands between May 2016 and June 2019. Starting between 8 and 15 weeks’ gestation, women took either 80 mg of aspirin or a placebo daily until 36 weeks’ gestation or delivery. Women also received progesterone, cerclage, or pessary as indicated according to local protocols.

The study enrolled 406 women with singleton pregnancy and a history of preterm birth delivered between 22 and 37 weeks’ gestation. The final analysis, after exclusions for pregnancy termination, congenital anomalies, multiples pregnancy, or similar reasons, included 193 women in the intervention group and 194 in the placebo group. The women had similar baseline characteristics across both groups except a higher number of past mid-trimester fetal deaths in the aspirin group.

“It’s important to realize these women had multiple preterm births, as one of our inclusion criteria was previous spontaneous preterm birth later than 22 weeks’ gestation, so this particular group is very high risk for cervical insufficiency as a probable cause,” Dr. Landman told attendees.

Among women in the aspirin group, 21.2% delivered before 37 weeks, compared with 25.4% in the placebo group (P = .323). The rate of spontaneous birth was 20.1% in the aspirin group and 23.8% in the placebo group (P = .376). Though still not statistically significant, the difference between the groups was larger when the researchers limited their analysis to the 245 women with at least 80% compliance: 18.5% of women in the aspirin group had a preterm birth, compared with 24.8% of women in the placebo group (P = .238).

There were no significant differences between the groups in composite poor neonatal outcomes or in a range of prespecified newborn complications. The aspirin group did have two stillbirths, two mid-trimester fetal losses, and two extremely preterm newborns (at 24+2 weeks and 25+2 weeks). The placebo group had two mid-trimester fetal losses.

“These deaths are inherent to the study population, and it seems unlikely they are related to the use of aspirin,” Dr. Landman said. “Moreover other aspirin studies have not found an increased perinatal mortality rate, and some large studies indicated the neonatal mortality rate is even reduced.”

Although preterm birth only trended lower in the aspirin group, Dr. Landman said the researchers believe they cannot rule out an effect from aspirin.

“It’s also important to note that our study was underpowered as the recurrence risk of preterm birth in our study was lower than expected, so it’s possible a small treatment effect of aspirin could not be demonstrated in our study,” she said. “And, despite the proper randomization procedure, many more women in the aspirin group had a previous mid-trimester fetal loss. This indicates that the aspirin group might be more at risk for preterm birth than the placebo group, and this imbalance could also have diminished a small protective effect of aspirin.”

In response to an audience question, Dr. Landman acknowledged that more recent studies on aspirin have used 100- to 150-mg dosages, but that evidence was not as clear when their study began in 2015. She added that her research team does not advise changing clinical care currently and believes it is too soon to recommend aspirin to this population.

Tracy Manuck, MD, MS, an associate professor of ob.gyn. at the University of North Carolina in Chapel Hill, agreed that it is premature to begin prescribing aspirin for preterm birth prevention, but she noted that most of the patients she cares for clinically already meet criteria for aspirin based on their risk factors for preeclampsia.

“Additional research is needed in the form of a well-designed and large [randomized, controlled trial],” Dr Manuck, who moderated the session, said in an interview. “However, such a trial is becoming increasingly difficult to conduct because so many pregnant women qualify to receive aspirin for the prevention of preeclampsia due to their weight, medical comorbidities, or prior pregnancy history.”

She said she anticipates seeing patient-level data meta-analyses in the coming months as more data on aspirin for preterm birth prevention are published.

“Given that these data are supportive of the overall trends seen in prior publications, I do think that low-dose aspirin will eventually bear out as a helpful preventative measure to prevent recurrent preterm birth. Aspirin is low risk, readily available, and is inexpensive,” Dr. Manuck said. “I hope that meta-analysis data will provide additional information regarding the benefit of low-dose aspirin for prematurity prevention.”

The research was funded by the Dutch Organization for Health Care Research and the Dutch Consortium for Research in Women’s Health. Dr. Landman and Dr. Manuck had no disclosures.

Women at risk of preterm birth who took daily low-dose aspirin did not have significantly lower rates of preterm birth than those who did not take aspirin, according to preliminary findings from a small randomized controlled trial. There was a trend toward lower rates, especially among those with the highest compliance, but the study was underpowered to detect a difference with statistical significance, said Anadeijda Landman, MD, of the Amsterdam University Medical Center. Dr. Landman presented the findings Jan. 28 at a meeting sponsored by the Society for Maternal-Fetal Medicine.

Preterm birth accounts for a third of all neonatal mortality, she told attendees. Among 15 million preterm births worldwide each year, 65% are spontaneous, indicating the need for effective preventive interventions. Dr. Landman reviewed several mechanisms by which aspirin may help reduce preterm birth via different pathways.

The researchers’ multicenter, placebo-controlled trial involved 8 tertiary care and 26 secondary care hospitals in the Netherlands between May 2016 and June 2019. Starting between 8 and 15 weeks’ gestation, women took either 80 mg of aspirin or a placebo daily until 36 weeks’ gestation or delivery. Women also received progesterone, cerclage, or pessary as indicated according to local protocols.

The study enrolled 406 women with singleton pregnancy and a history of preterm birth delivered between 22 and 37 weeks’ gestation. The final analysis, after exclusions for pregnancy termination, congenital anomalies, multiples pregnancy, or similar reasons, included 193 women in the intervention group and 194 in the placebo group. The women had similar baseline characteristics across both groups except a higher number of past mid-trimester fetal deaths in the aspirin group.

“It’s important to realize these women had multiple preterm births, as one of our inclusion criteria was previous spontaneous preterm birth later than 22 weeks’ gestation, so this particular group is very high risk for cervical insufficiency as a probable cause,” Dr. Landman told attendees.

Among women in the aspirin group, 21.2% delivered before 37 weeks, compared with 25.4% in the placebo group (P = .323). The rate of spontaneous birth was 20.1% in the aspirin group and 23.8% in the placebo group (P = .376). Though still not statistically significant, the difference between the groups was larger when the researchers limited their analysis to the 245 women with at least 80% compliance: 18.5% of women in the aspirin group had a preterm birth, compared with 24.8% of women in the placebo group (P = .238).

There were no significant differences between the groups in composite poor neonatal outcomes or in a range of prespecified newborn complications. The aspirin group did have two stillbirths, two mid-trimester fetal losses, and two extremely preterm newborns (at 24+2 weeks and 25+2 weeks). The placebo group had two mid-trimester fetal losses.

“These deaths are inherent to the study population, and it seems unlikely they are related to the use of aspirin,” Dr. Landman said. “Moreover other aspirin studies have not found an increased perinatal mortality rate, and some large studies indicated the neonatal mortality rate is even reduced.”

Although preterm birth only trended lower in the aspirin group, Dr. Landman said the researchers believe they cannot rule out an effect from aspirin.

“It’s also important to note that our study was underpowered as the recurrence risk of preterm birth in our study was lower than expected, so it’s possible a small treatment effect of aspirin could not be demonstrated in our study,” she said. “And, despite the proper randomization procedure, many more women in the aspirin group had a previous mid-trimester fetal loss. This indicates that the aspirin group might be more at risk for preterm birth than the placebo group, and this imbalance could also have diminished a small protective effect of aspirin.”

In response to an audience question, Dr. Landman acknowledged that more recent studies on aspirin have used 100- to 150-mg dosages, but that evidence was not as clear when their study began in 2015. She added that her research team does not advise changing clinical care currently and believes it is too soon to recommend aspirin to this population.

Tracy Manuck, MD, MS, an associate professor of ob.gyn. at the University of North Carolina in Chapel Hill, agreed that it is premature to begin prescribing aspirin for preterm birth prevention, but she noted that most of the patients she cares for clinically already meet criteria for aspirin based on their risk factors for preeclampsia.

“Additional research is needed in the form of a well-designed and large [randomized, controlled trial],” Dr Manuck, who moderated the session, said in an interview. “However, such a trial is becoming increasingly difficult to conduct because so many pregnant women qualify to receive aspirin for the prevention of preeclampsia due to their weight, medical comorbidities, or prior pregnancy history.”

She said she anticipates seeing patient-level data meta-analyses in the coming months as more data on aspirin for preterm birth prevention are published.

“Given that these data are supportive of the overall trends seen in prior publications, I do think that low-dose aspirin will eventually bear out as a helpful preventative measure to prevent recurrent preterm birth. Aspirin is low risk, readily available, and is inexpensive,” Dr. Manuck said. “I hope that meta-analysis data will provide additional information regarding the benefit of low-dose aspirin for prematurity prevention.”

The research was funded by the Dutch Organization for Health Care Research and the Dutch Consortium for Research in Women’s Health. Dr. Landman and Dr. Manuck had no disclosures.

Women at risk of preterm birth who took daily low-dose aspirin did not have significantly lower rates of preterm birth than those who did not take aspirin, according to preliminary findings from a small randomized controlled trial. There was a trend toward lower rates, especially among those with the highest compliance, but the study was underpowered to detect a difference with statistical significance, said Anadeijda Landman, MD, of the Amsterdam University Medical Center. Dr. Landman presented the findings Jan. 28 at a meeting sponsored by the Society for Maternal-Fetal Medicine.

Preterm birth accounts for a third of all neonatal mortality, she told attendees. Among 15 million preterm births worldwide each year, 65% are spontaneous, indicating the need for effective preventive interventions. Dr. Landman reviewed several mechanisms by which aspirin may help reduce preterm birth via different pathways.

The researchers’ multicenter, placebo-controlled trial involved 8 tertiary care and 26 secondary care hospitals in the Netherlands between May 2016 and June 2019. Starting between 8 and 15 weeks’ gestation, women took either 80 mg of aspirin or a placebo daily until 36 weeks’ gestation or delivery. Women also received progesterone, cerclage, or pessary as indicated according to local protocols.

The study enrolled 406 women with singleton pregnancy and a history of preterm birth delivered between 22 and 37 weeks’ gestation. The final analysis, after exclusions for pregnancy termination, congenital anomalies, multiples pregnancy, or similar reasons, included 193 women in the intervention group and 194 in the placebo group. The women had similar baseline characteristics across both groups except a higher number of past mid-trimester fetal deaths in the aspirin group.

“It’s important to realize these women had multiple preterm births, as one of our inclusion criteria was previous spontaneous preterm birth later than 22 weeks’ gestation, so this particular group is very high risk for cervical insufficiency as a probable cause,” Dr. Landman told attendees.

Among women in the aspirin group, 21.2% delivered before 37 weeks, compared with 25.4% in the placebo group (P = .323). The rate of spontaneous birth was 20.1% in the aspirin group and 23.8% in the placebo group (P = .376). Though still not statistically significant, the difference between the groups was larger when the researchers limited their analysis to the 245 women with at least 80% compliance: 18.5% of women in the aspirin group had a preterm birth, compared with 24.8% of women in the placebo group (P = .238).

There were no significant differences between the groups in composite poor neonatal outcomes or in a range of prespecified newborn complications. The aspirin group did have two stillbirths, two mid-trimester fetal losses, and two extremely preterm newborns (at 24+2 weeks and 25+2 weeks). The placebo group had two mid-trimester fetal losses.

“These deaths are inherent to the study population, and it seems unlikely they are related to the use of aspirin,” Dr. Landman said. “Moreover other aspirin studies have not found an increased perinatal mortality rate, and some large studies indicated the neonatal mortality rate is even reduced.”

Although preterm birth only trended lower in the aspirin group, Dr. Landman said the researchers believe they cannot rule out an effect from aspirin.

“It’s also important to note that our study was underpowered as the recurrence risk of preterm birth in our study was lower than expected, so it’s possible a small treatment effect of aspirin could not be demonstrated in our study,” she said. “And, despite the proper randomization procedure, many more women in the aspirin group had a previous mid-trimester fetal loss. This indicates that the aspirin group might be more at risk for preterm birth than the placebo group, and this imbalance could also have diminished a small protective effect of aspirin.”

In response to an audience question, Dr. Landman acknowledged that more recent studies on aspirin have used 100- to 150-mg dosages, but that evidence was not as clear when their study began in 2015. She added that her research team does not advise changing clinical care currently and believes it is too soon to recommend aspirin to this population.

Tracy Manuck, MD, MS, an associate professor of ob.gyn. at the University of North Carolina in Chapel Hill, agreed that it is premature to begin prescribing aspirin for preterm birth prevention, but she noted that most of the patients she cares for clinically already meet criteria for aspirin based on their risk factors for preeclampsia.

“Additional research is needed in the form of a well-designed and large [randomized, controlled trial],” Dr Manuck, who moderated the session, said in an interview. “However, such a trial is becoming increasingly difficult to conduct because so many pregnant women qualify to receive aspirin for the prevention of preeclampsia due to their weight, medical comorbidities, or prior pregnancy history.”

She said she anticipates seeing patient-level data meta-analyses in the coming months as more data on aspirin for preterm birth prevention are published.

“Given that these data are supportive of the overall trends seen in prior publications, I do think that low-dose aspirin will eventually bear out as a helpful preventative measure to prevent recurrent preterm birth. Aspirin is low risk, readily available, and is inexpensive,” Dr. Manuck said. “I hope that meta-analysis data will provide additional information regarding the benefit of low-dose aspirin for prematurity prevention.”

The research was funded by the Dutch Organization for Health Care Research and the Dutch Consortium for Research in Women’s Health. Dr. Landman and Dr. Manuck had no disclosures.