Self-Reported Marijuana Use During Pregnancy: A Tangled Web?

With the advent of its legalization, cannabis use has become more common — but how does this trend apply to pregnant women? To evaluate self-reported cannabis use during pregnancy as well as associated adverse outcomes, investigators in Ontario reviewed records of >650,000 women delivering between 2012 and 2017. In a matched cohort design controlling for other differences between women who did or did not report cannabis use, risk for preterm birth at <37 weeks' gestation was 41% higher among cannabis users. Other excess risks included placental abruption (72% higher), small for gestational age (53%), NICU transfer (40%), and 5-minute Apgar scores <4 (28%).

In another study, U.S. investigators used the National Survey on Drug Use and Health t…