Pregnancy presents a special problem to the clinician treating bipolar disorders in women. Since the first episode of mania typically occurs before the age of 30, many women in their prime childbearing years may be exposed to potentially teratogenic mood-stabilizing agents. This exposure may also continue for the nursing infant during lactation. Pregnancy itself can exacerbate bipolar symptoms and also alter the pharmacokinetics of mood-stabilizing drugs. Risks to mother and fetus can be reduced with a number of simple strategies, including monotherapy with the lowest effective dose of a drug for the shortest period necessary, periconceptional use of multivitamins with folate, prescription of drugs with established safety records, and avoidance of exposure to antimanic agents during the first trimester of pregnancy. In this article, we review existing evidence on the risks to fetuses and nursing infants of mothers taking specific mood-stabilizing agents, and we present appropriate management guidelines designed to minimize these risks.