Depression affects women almost twice as often as men, with about one in four women suffering from it in her lifetime. While depression may strike at any time, studies show that women are particularly vulnerable during their childbearing years.
Early reports suggested that women with bipolar disorder may be at lower risk for onset or relapse of this disorder during pregnancy and that some women may be able to remain well during pregnancy despite medication discontinuation. However, more recent studies have suggested that recurrence of affective illness during pregnancy is relatively common among women with bipolar disorder. Dr. Adele Viguera and her colleagues at the Center for Women's Mental Health reported that among pregnant bipolar women, relapse rates were very high (58%) in those women who discontinued maintenance treatment with lithium during pregnancy (Viguera et al 2000).
Because rates of postpartum illness are very high in women with bipolar disorder, it is generally recommended that mothers continue treatment with a mood stabilizer throughout the postpartum period to reduce their risk of relapse; however, the use of medications during the postpartum period is complicated by the issue of breastfeeding. All medications are secreted into the breast milk, although their concentrations appear to vary (Chaudron and Jefferson, 2000).
Unfortunately the mood stabilizers most commonly used to treat bipolar disorder (including lithium and valproic acid) can increase the risk of certain types of congenital malformations in children exposed to these medications during the first trimester of pregnancy. For women who need a mood stabilizer during pregnancy, lithium is the safest option; however, when used during the first trimester, it carries a 0.1% risk of a cardiac malformation called Ebstein's anomaly. Although this is a potentially serious complication, it is important to keep in mind that the risk of malformation is relatively small.
For women with bipolar disorder who are planning a pregnancy, it is common practice to discontinue mood stabilizers prior to attempts to conceive, since the mood stabilizers most commonly used to treat bipolar disorder (lithium, valproic acid, and carbamazepine) all carry some risk of birth defect. The problem with this approach is that, after discontinuation of maintenance treatment, a woman is at very high risk for relapse. The longer it takes to get pregnant and the longer she remains off medication, the greater is her risk for having recurrent illness.
