Study: Using cannabis during pregnancy can predispose babies to stress and anxiety

According to New York researchers pregnant women who use cannabis, to relieve stress and anxiety, for example, could inadvertently predispose their babies to these two pathologies.

Researchers at’Icahn School of Medicine at Mount Sinai and City University of New York (CUNY) are based on the premise that «the impact of maternal cannabis use on fetal and infant development is unclear».

They therefore examined placental gene expression as well as the behavior and physiology of young children in a long-term study of 322 mother-child pairs, all from an ongoing study of stress during pregnancy.

Around the age of six, hair samples from the children were taken to measure hormone levels, electrocardiogram recordings were used to assess their cardiac function under stressful conditions, and parental surveys were conducted to determine their behavior and emotional functioning.

Compared to the children of non-cannabis users, the children of mothers who had used cannabis during pregnancy showed higher levels of anxiety, aggression, hyperactivity and the stress hormone cortisol.

In addition, exposure was associated with a reduction in the high-frequency component of the variation in the time interval between heartbeats and, for a subset of participants, RNA sequencing of placental tissue taken at birth «revealed that maternal cannabis use was associated with lower expression of immune-activating genes», which help provide protection against pathogens.

«Cannabis-linked deletion of several placental immune gene networks predicted greater anxiety in children.», reports university.

«Future studies are needed to examine the effects of cannabis on immune function during pregnancy as a potential regulatory mechanism for neurobehavioral development,» the authors write in the study abstract.

Yoko Nomura, first author of the paper and professor of psychology at CUNY, said in the university's press release that it has been shown that cannabinoids plays a role in stress modulation.

That said, «our study shows that exposure in utero to cannabis has the opposite effect on children, causing them to exhibit increased levels of anxiety, aggression and hyperactivity compared to other children who were not exposed to cannabis during pregnancy,» reports Nomura.

Because cannabis is more potent than it was a few decades ago, «our results indicate that its use during pregnancy may have a long-term impact on children,» notes Yasmin Hurd, Ph.D., lead author of the paper and director of the Mount Sinai Institute of Addictions.

«The study results underscore the need for unbiased education and awareness of the public and certain vulnerable populations of pregnant women regarding the potential impact of cannabis use,» adds Hurd.