Pregnancy exposure to olanzapine, quetiapine, risperidone, aripiprazole and risk of congenital malformations. A systematic review.

To review available data on first-trimester exposure to olanzapine, quetiapine, risperidone and aripiprazole and risk of congenital malformations. We performed a systematic literature search in accordance with PRISMA guidelines identifying studies containing original data on first-trimester exposure and pregnancy outcome with respect to congenital malformations. Cumulated data for olanzapine were 1090 first-trimester-exposed pregnancies with 38 malformations resulting in a malformation rate of 3.5%. The corresponding numbers for quetiapine, risperidone and aripiprazole were 443/16 (3.6%), 432/22 (5.1%) and 100/5 (5.0%), respectively. Relative risk estimates and 95% confidence intervals were 1.0 (0.7-1.4) (olanzapine), 1.0 (0.6-1.7) (quetiapine), 1.5 (0.9-2.2) (risperidone) and 1.4 (0.5-3.1) (aripiprazole). First-trimester exposure to olanzapine is not associated with an increased risk of congenital malformation. Data for quetiapine and risperidone do not suggest a substantially increased risk, while the risk estimate for aripiprazole remains imprecise owing to a low amount of data.