Bipolar disorder is a chronic condition characterized by periods of mania, depression, or mixed states (co-occurring mania and depression). The postpartum period is associated with a high risk for symptom relapse or intensification, which can be reduced with the use of medications. Abrupt discontinuation of these medications increases the probability of relapse, which is associated with high-risk behaviors, significant family dysfunction, and suicide. Drugs used to treat patients with bipolar disorder vary in teratogenic potential. Although first trimester lithium use is associated with Ebstein's anomaly, the risk was overestimated in the past. Valproate and its derivatives and carbamazepine are human teratogens. Lamotrigine does not negatively impact major reproductive outcomes, but the data are limited. Typical antipsychotic medications are relatively well studied and the data do not identify major morphologic teratogenicity. There are fewer studies of newer atypical antipsychotic medications, and registries have been developed to collect prospective data. Clinical management of bipolar disorder during pregnancy, postpartum, and lactation requires a careful balancing of maternal and fetal risks and benefits. Communication and careful comanagement between the obstetric and psychiatric team is essential when treating women with bipolar disorder during the reproductive years.