A new study on mothers’ use of marijuana during pregnancy found links to a small increase in the child’s risk of developing a range of problems, including psychopathology, low birth weight and sleep problems.
Coming just over a year after the U.S. surgeon general warned that women who are pregnant or planning to become pregnant should not use marijuana, the new study adds to the slowly growing scientific evidence bolstering the case for the government’s caution against using it while pregnant or breastfeeding.
As of last March, cannabis was legal in some fashion in all but four states. But it remains a Class I controlled substance under federal law, the same as heroin, ecstasy and LSD.
The increasingly permissive attitude toward marijuana’s use has been said to lead many people to conclude that it is a benign substance. Public health officials say some health care professionals and dispensaries even advise women to use it to ward off some of the discomfort of pregnancy.
The new study, though, recommends that professionals, the industry, family and friends of pregnant women should actively discourage cannabis use in these cases.
“Women refraining from cannabis use during pregnancy may benefit offspring,” concluded the peer-reviewed study led by three researchers at Washington University in St. Louis and published in this week’s online journal JAMA Psychiatry.
The researchers used information gleaned from the National Institute of Mental Health’s adolescent brain cognitive development database. They looked at data on 11,489 children, of whom 655, or 5.7%, were exposed to cannabis prenatally. After controlling for multiple variables, the study concluded that women who use cannabis while pregnant subjected the child to a slightly elevated risk of developing problems, as compared with children who are not prenatally exposed.
The authors said they were aware of no larger study of its kind, but noted that the team did not delve into important questions such as the effects of the frequency of the mother’s cannabis use, the method of drug delivery, the strain of cannabis used and the dosage.
“It is clear that more studies on the association between prenatal cannabis exposure and offspring developmental outcomes are needed to examine potential causal effects, moderating or protective factors and biological mechanisms,” the authors wrote.