Study Holds Good News for 8% of Pregnant Women It finds antidepressants don't raise risk of heart defects By Kate Seamons, Newser Staff Posted Jun 19, 2014 8:49 AM CDT 6 comments Comments Study finds antidepressants don't raise risk of heart defects. (?) (Newser) – An estimated 8% to 13% of pregnant woman are on antidepressants, and not without warning: The FDA in 2005 amended antidepressants' labels to indicate that babies born to moms taking them could suffer an increased risk of heart defects. But causation hadn't been proven, and the latest study on the topic indicates those warnings may be baseless. The latest study, published in the New England Journal of Medicine, followed 949,504 pregnant women, 64,389 (6.8%) of whom used antidepressants during the first trimester—the period of the most rapid cell division, when the risk of developing such defects is highest, WebMD explains. What Krista Huybrechts of Brigham and Women's Hospital did differently: She and her team took into consideration factors that could lead to heart defects, like the mother's age and whether she had diabetes. The Boston Herald reports that among babies whose mothers did not take antidepressants, 72.3 per 10,000 were born with a cardiac defect, compared with 90.1 per 10,000 infants whose mothers did. After controlling for risk factors, "there is no evidence to support a substantial increased risk of cardiac malformations overall," says Huybrechts. Still, she cautions that antidepressant use during pregnancy poses a "whole range of other potential adverse outcomes." To wit, one expert pointed to "serious flaws" with the study. For one, it didn't flag miscarriages, which are linked to antidepressants. "It may be that the most severely affected pregnancies are miscarrying," he noted.