SAN FRANCISCO — Women who used marijuana during pregnancy were significantly less likely to view it as risky even in a state where it was not legalized, according to prospectively collected data presented at the annual clinical and scientific meeting of the American College of Obstetricians and Gynecologists. But most of those women had not received any counseling about stopping its use, and more than half wanted more information about its effects on pregnancy complications.
“The biggest thing we recognized was that our counseling in prenatal visits was lower than what it really should have been,” Abigail M. Ramseyer, DO, of University of Michigan Health– Sparrow in Lansing, said in an interview. She said doctors really need to be asking their patients about marijuana use and having a conversation about the risks of its use during pregnancy.
An estimated 3%-30% of pregnant women use marijuana, depending on the population, but prevalence has been rising as more states legalize its use. Yet research has shown an association between marijuana use during pregnancy and multiple neonatal complications, including fetal growth restriction and low birth weight.
Pregnant women at a single center in Arkansas were invited during their prenatal visits to complete a 35-question, anonymous survey electronically or on paper. Of the 460 approached, 88.7% completed the survey and 11.8% of those women reported use of marijuana during pregnancy. Among those who used it while pregnant, 50% reported using it 2-3 times a week, 27% reported using it once weekly, and 18.8% reported using it daily.
The women who used it while pregnant were less likely to have a college degree and half (50%) were aged 18-24, with use declining with increasing age. A third of those who use it were White (33.3%), 52.1% were Black, and 6.3% were Hispanic.
More than half of the women (52.7%) who used marijuana during pregnancy reported that there had not been any discussion about substance use during pregnancy at the prenatal visit, and 82.4% said they had not received any counseling about stopping its use during pregnancy. Yet 54% of them wanted more information about pregnancy complications linked to cannabis use.
The other questions asked respondents on a 5-point Likert scale how much they agreed or disagreed with various statements related to perceptions of marijuana, its use during pregnancy, and its risks.
Most respondents strongly agreed that “marijuana isn’t as bad as other drugs like heroin, cocaine or meth,” but average agreement was higher among those who used marijuana (4.88) than who didn’t (4.02, P < .001).
Respondents largely neither agreed nor disagreed with its being okay to use marijuana during pregnancy with a prescription, but agreement was still higher among those who used it (3.68) than didn’t use it (2.82, P < .001). Those who used marijuana were more likely to agree that it’s “a natural substance and not a drug” (4.67 vs. 3.38, P < .001); to believe “marijuana has minimal health risks during and outside of pregnancy” (4.15 vs. 2.96, P < .001); and to believe “marijuana has less risk for treating symptoms in pregnancy than prescription medication from my provider” (4.19 vs. 3.01, P < .001).
It was not surprising that patients using marijuana would have more favorable opinions toward legalizing it, Dr. Ramseyer said, but it was interesting that the respondents’ attitude overall, regardless of use, was positive in a fairly conservative state where it was still illegal. She said her research group has data they are starting to analyze about the perceptions of patients’ partners and family members regarding marijuana use during pregnancy.
Animesh Upadhyay, MD, a resident at Yale–New Haven Medical Center in Connecticut, was also surprised by how positive the attitudes toward marijuana use and legalization were in a state where it’s illegal.
“The thing that disturbs me is that nobody has spoken about the risks of marijuana in pregnancy” to many of the respondents, said Dr. Upadhyay, who was not involved in the study. Based on the findings, Dr. Upadhyay said he would definitely begin asking patients more about their use of marijuana and their beliefs about it.
In a separate poster, Sarah Dzubay, BS, of Oregon Health & Science University, Portland, presented data examining potential associations between cannabis use and fertility. Previous research has suggested an association, but the cross-sectional analysis by Ms. Dzubay identified only a nonsignificant trend toward an association.
The researchers analyzed data from the 2013-2018 National Health and Nutrition Examination Study (NHANES) for woman aged 20-49 based on self-reported use of cannabis. Among 3166 women, 51% reported never using cannabis, 29% reported irregular use, and 20% reported regular use at least monthly.
“Women reporting regular use were younger, of lower income and educational attainment, and more likely to be single,” Ms. Dzubay reported. Those reporting irregular use, meanwhile, were more likely to be college graduates.
More of the women who used cannabis regularly (15.4%) reported an inability to conceive within one year than women who used cannabis irregularly (10.8%) or never (12.6%). The higher odds ratio of infertility among those using cannabis regularly (OR 1.47) compared to never using it was not statistically significant, however, nor was the reduced odds ratio among those using it irregularly (OR 0.83).
Because the results were not significant, the possibility of a link to infertility is “something to keep in mind,” Ms. Dzubay said, but “a lot more data has to be collected about this question before we can definitively say there’s a risk.”
The authors and Dr. Upadhyay had no disclosures. Neither study noted any external funding.