To the Editor: We thank Dr. Rifkin for raising important issues regarding the optimal care of pregnant women with bipolar disorder. We found that two-thirds of illness recurrences during pregnancy after discontinuation of maintenance lithium treatment were depressive and that depression is the major source of morbidity and mortality in bipolar disorder (1). Optimal management of bipolar depression, even in nonpregnant patients, has only recently been studied in a systematic fashion. However, the suggestion by Dr. Rifkin that prophylactic antidepressant treatment theoretically might be beneficial in the absence of coadministration of a mood stabilizer raises obvious concern with respect to risk for induction of dangerous maternal affective instability with attendant morbidity and uncertain effects on the fetus. In the study group on which we reported, we noted that reintroduction of lithium monotherapy was most often sufficient to restore euthymia. For patients who relapse into mania during pregnancy after discontinuation of a mood stabilizer, reintroduction of the mood stabilizer with adjunctive antipsychotics can also be used with relative safety. ECT may also be used to treat mania as well as depression during pregnancy when expeditious treatment is imperative (2).