During pregnancy, up to 70% of women experience depressive symptoms and 10% to 16% fulfill the DSM-IV diagnostic criteria for MD. These prevalence rates are very similar to those in the general population, suggesting that pregnancy per se does not increase the risk of depression. A large prospective controlled study evaluated 182 pregnant and 179 nonpregnant women using Research Diagnostic Criteria for major and minor depression. The rates of depression were equal in both groups, again suggesting that pregnancy does not affect the risk of depression.
In women from the second trimester through 9 weeks postpartum, the highest level of depressive symptomatology occurred at weeks 34 to 38 of gestation. As shown in Table 5, several risk factors for depression during pregnancy have been identified. Various medical disorders, such as anemia, gestational diabetes, and thyroid dysfunction, may also contribute to depressive symptoms in pregnancy.
Management of MD during pregnancy may include nonpharmacologic interventions, such as cognitive therapy or electroconvulsive therapy (ECT), and/or antidepressant medications. ECT is a relatively safe and effective treatment for MD in pregnant women, particularly in high-risk situations, such as mania and psychotic depression.[40,41] Pharmacologic interventions mainly include the use of antidepressant agents.
A meta-analysis failed to find any evidence for teratogenicity for antidepressants during pregnancy. Recurrence rates for patients with MD during pregnancy are estimated to be as high as 50% within 6 months following discontinuation of antidepressant treatment.[43,44] Therefore, antidepressant prophylaxis in these patients may be reasonable. Adjustment of antidepressant dosages during pregnancy may be needed, because antidepressant levels have been reported to decrease during pregnancy, possibly as a result of pregnancy-associated altered volume of distribution.