The effect of various antipsychotics during pregnancy has repeatedly been studied, but for most atypical antipsychotics, only little information is available. We identified from the Swedish Medical Birth Register 2908 women who had reported the use of any antipsychotic or lithium in early pregnancy and studied malformation rates with data also from the Register of Congenital Malformations and the Hospital Discharge Register. Comparisons were made with all births (n = 958,729) after adjustment for some confounders. Risks were expressed as odds ratios (ORs).
Most women had used dixyrazine or prochlorperazine mainly because of nausea and vomiting in early pregnancy. Seventy-nine women had used lithium, and these outcomes are reported separately. Hence, the main analysis was restricted to 570 women (576 infants) using other antipsychotics. There was a statistically significant increase in the risk for a congenital malformation-after exclusion of some common and minor conditions, the OR was 1.52 (95% confidence interval, 1.05-2.19). Exclusion of infants exposed to anticonvulsants reduced the OR only slightly. Most of the increased risk was caused by cardiovascular defects, mainly atrium or ventricular septum defect. No certain drug specificity was found. Except for an increased risk for congenital malformations, a nearly doubling of the risk for gestational diabetes and a 40% increased risk for cesarean delivery was noted. Because there seems to be little drug specificity, it is possible that underlying pathology or unidentified confounding explains the excess risk.