A government-funded study suggests that taking antidepressants during pregnancy may not substantially increase women's risk of delivering babies with heart defects. The findings run counter to prevailing beliefs about the safety of antidepressant use during pregnancy and could affect treatment for the 10% to 15% of pregnant women who suffer from depression. The study, published in The New England Journal of Medicine, involved analyses of Medicaid records for nearly 950,000 women who gave birth between 2000 and 2007. Overall, researchers found that infants were 25% more likely to have heart defects if their mothers used selective serotonin-reuptake inhibitors -- the most common type of antidepressant -- during their first trimester. However, when the investigators restricted their analyses to women diagnosed with depression -- to control for the potential effect of underlying illness or related factors -- the increased risk was only 12%. When they further controlled for depression severity and other potential confounders, the increased risk was only 6% with a low absolute risk. Read the abstract.