There are many pertinent issues surrounding the treatment of bipolar disorder during pregnancy. Unfortunately, while there are numerous observational reports in the literature, there is not a lot of information concerning the safety and efficacy of particular treatments or the nontreatment of bipolar disorder during pregnancy. Much of the existing data comes from the neurology literature regarding epilepsy. In this review, we summarize the available evidence regarding the safety and efficacy of using the anticonvulsants carbamazepine and valproic acid during pregnancy. The available data suggest that there is a possibility of risk of major malformations with the anticonvulsants. The risk is probably higher with valproic acid than carbamazepine. In this article lithium is not discussed, although there are a number of concerns about lithium's potential teratogenicity, and it has been implicated in Epstein's anomaly, a congenital heart defect among infants born to women taking lithium; as with other medications, however, the data have specific limitations.