SCIENTIFIC AMERICAN – As with most decision points around pregnancy, cannabis use is a fraught subject.
Researchers can’t assess it in randomized trials because dosing pregnant people with the psychoactive substance is unethical.
The next best thing is studies with enough participants who use cannabis on their own, allowing for comparisons with those who do not.
The findings of one such study, published on November 15 in the Proceedings of the National Academy of Sciences USA, highlight symptoms of increased anxiety, hyperactivity and aggression in children whose parents used cannabis during pregnancy.
And its analysis of placental tissue points to changes in the activity of immunity-related genes.
Today pregnant people “are being bombarded with a lot of ads to treat nausea and anxiety during pregnancy” with cannabis, says the paper’s senior author Yasmin Hurd, director of the Addiction Institute at Mount Sinai.
“Our studies are about empowering them with knowledge and education so that they can make decisions.”
The results are “very striking, very much a first,” says Daniele Piomelli, a professor and director of the Center for the Study of Cannabis at the University of California, Irvine, who was not involved in the work.
Pregnancy studies in rodents and even in sheep, which have a placenta more like ours, have required cautious interpretations of findings that show effects on offspring behavior and function, he says. The new study is one of the first to tackle the question in people “in a systematic way,” Piomelli adds.
Hurd and her colleagues worked with 322 parent-child pairs, beginning with profiles of genetic activity in placental samples taken at birth. When the children reached about three years of age, samples of their hair were tested for levels of stress hormones.
From ages three to six, they also underwent recordings of their heart-rate variability … READ MORE.