New research offers more insight into potentially dangerous racial disparities in cesarean deliveries: In first-time live births, healthy African-American and Hispanic mothers were 21% and 26% more likely than White mothers, respectively, to deliver by cesarean section despite being low risk. The higher number of cesareans appeared to boost their risk of morbidity.
“A 20% increased odds of cesarean among otherwise healthy, low-risk, nulliparous individuals at term – with limited medical or obstetric explanation – is a significant concern, especially when considering that cesarean is the most common surgical procedure in the U.S.,” said study author Michelle P. Debbink, MD, PhD, an assistant professor with the department of obstetrics and gynecology at the University of Utah, in an interview.
Dr. Debbink and colleagues launched the study, published in the Jan. 2022 issue of Obstetrics & Gynecology, to better understand the racial gap in cesarean sections, which are considered riskier than vaginal deliveries. “Several studies have shown that Black women undergo cesarean more frequently than non-Hispanic White women. Numerous studies also show that Hispanic/Latina women undergo cesarean more frequently than White women, although these data are a bit more mixed,” she said. “What we don’t know, however, is why these differences occur and whether there are clues in the data which can point us toward interventions to close the gap.”
One theory, she said, is that Black and Hispanic women have more comorbidities and therefore more cesareans. To test that idea, the researchers found a cohort of healthy women in a randomized trial that studied the induction of labor.
For the study, they focused on 5,759 women (24.3% Black, 30% Hispanic, 46.6% White). Major differences between the groups included maternal age (average = 21 for Black, 22 for Hispanic, and 26 for White, P < .001), private insurance (17% for Black and Hispanic, 75% for White; P < .001), and full or part-time employment (37% for Black, 31% for Hispanic, and 71% for White; P < .001).
A total of 1,158 of the women (20.1%) underwent cesarean deliveries, accounting for 23% of deliveries by Black women, 22.8% of those by Hispanic women, and 17.6% of those by White women (P < .001). Black women were 21% more likely than White women to give birth via cesarean (adjusted relative risk = 1.21, 95% CI: 1.03-1.42) and Hispanic women were 26% more likely (aRR = 1.26, 95% CI: 1.08-1.46).
The study doesn’t explore why Black and Hispanic women have more cesarean deliveries. However, Dr. Debbink said, “we hypothesize that the difference likely stems more from differing treatment of Black or Hispanic individuals during labor.” It’s unlikely, she said, that these women are more likely to prefer cesarean sections. For one thing, she said, other research hasn’t shown a difference in preferences by race.
The researchers also analyzed maternal morbidity, defined as “transfusion of 4 or more units of red blood cells, any transfusion of other products, postpartum infection, intensive care unit admission, hysterectomy, venous thromboembolism, or maternal death.”
The study found that while few women (2.3%) suffered from morbidity, Black (aRR = 2.05, 95% CI: 1.21-3.47) and Hispanic (aRR = 1.92, 95% CI: 1.17-3.14) women were more likely to suffer from it than White women.
The researchers report that “cesarean birth accounted for an estimated 15.8% (95% CI: 2.1%-48.7%) and 16.5% (95% CI: 4.0%-44.0%) of excess maternal morbidity among non-Hispanic Black and Hispanic people, respectively.”
“Both endometritis and wound complications are much more common among individuals with cesarean, and blood clots, hysterectomy, and ICU admission are also more common after cesarean compared with vaginal delivery,” Dr. Debbink said.
The message of the study, she said, is that the health care system “perpetuates gaps in cesarean delivery for Black and Hispanic individuals compared to White individuals” even in low-risk, first-time live births. “We do not yet know exactly what the right levers are to address this gap, but it is important that we ob-gyns examine our practice patterns and our hospitals’ practice patterns to ensure equity for all our patients.”
Rebecca Delafield, PhD, an assistant professor of Native Hawaiian Health at the University of Hawaii, praised the study as “well-conducted” in an interview. “I agree with the assessment that while the cesarean delivery accounts for a modest proportion of excess morbidity in this study, the impact at the population level is significant,” said Dr. Delafield, who studies health disparities and didn’t take part in the study. “Delivery is complex and the causes of disparities observed are likely multifactorial, therefore research such as this is necessary and compelling.”
She added: “It is becoming increasingly evident that studies investigating racial/ethnic disparities in cesarean delivery and other maternal health outcomes must look beyond maternal behavioral or medical risk factors – e.g., obesity or hypertension – and consider the contribution of a broader set of factors, including societal prejudices.”
The study is funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Center for Advancing Translational Sciences. One study author reports funding from GlaxoSmithKline, Pfizer, Moderna, and UpToDate (contributor) and from the Centers for Disease Control and Prevention (via her institution). Dr. Debbink, the other authors, and Dr. Delafield report no disclosures.