Cannabis Use During Pregnancy May Affect Child Development, Study Says

In recent years, cannabis has been increasingly legalized across the globe, and, consequently, it has become a popular method of self-care, from balms that help provide muscle relaxation to bath products that help promote sleep. But, while many swear by the calming effects of the plant, one study is finding it’s yet another thing pregnant women may want to steer clear of.

The study was conducted by researchers from the Icahn School of Medicine at Mount Sinai and the City University of New York and published last month in Proceedings of the National Academy of Science (PNAS). It looked at 322 mother-child pairs from an ongoing New York City study of stress in pregnancy (started in 2009). The researchers looked at gene patterns in the placenta of these women, as well as early childhood behavior in their children. They measured the kids’ hormone levels at age 6, as well as used electrocardiogram recordings to measure heart functions when the child was faced with stress. The researchers also asked parents to fill out a questionnaire assessing their child’s behavioral and emotional functioning.

The study found that the children of mothers who used cannabis during pregnancy had higher levels of anxiety, aggression, hyperactivity, and the stress hormone cortisol. Additionally, they were more sensitive to stress. Looking at the placental tissue of the mothers (collected during birth), the researchers found that cannabis use was associated with lower levels of genes that build immunity, like pro-inflammatory cytokines, which help in protection against disease-causing bacteria and viruses.

According to the researchers, cannabis has become one of the most used recreational drugs amongst pregnant women. While the study is small, the researchers caution that cannabis use could have adverse effects on fetal and childhood development.

“We know that cannabinoid signaling plays a role in modulating stress, which is why some people use cannabis to reduce anxiety and relax,” Yoko Nomura, Professor of Psychology at CUNY Graduate Center and Queens College and first author of the paper said in a press release. “But our study shows that in utero exposure to cannabis has the opposite effect on children, causing them to have increased levels of anxiety, aggression, and hyperactivity compared to other children who were not exposed to cannabis during pregnancy.”

“Pregnant women are being bombarded with misinformation that cannabis is of no risk, while the reality is that cannabis is more potent today than it was even a few years ago. Our findings indicate that using it during pregnancy can have long-term impact on children,” Yasmin Hurd, PhD, the Ward-Coleman Chair of Translational Neuroscience, Director of the Addiction Institute at Mount Sinai and senior author of the paper, also said. “The study results underscore the need for nonbiased education and outreach to the public and particular vulnerable populations of pregnant women regarding the potential impact of cannabis use. Disseminating this data and accurate information is essential to improving the health of women and their children.”