Pregnancy has frequently been described as a time of affective well-being. However, a growing literature suggests that women are neither "protected" against new-onset or recurrence of depression during this time. Diagnosis and effective treatment of depression during pregnancy requires a careful weighing of risk of treatment which may include psychotropic medications against the risks associated with failure to adequately manage affective distress and its potential impact of maternal and fetal well-being. Treatment options during pregnancy are reviewed in the context of developing the most appropriate risk/benefit decision for individual patients with past or current depression who either anticipate pregnancy or who become pregnant.