 The pregnancy and postpartum periods are times of remarkable emotional and physical change for a woman, making pregnant women more vulnerable to mood swings and depressive symptoms. It is estimated that approximately 10 to 15 of pregnant women experience depression, which can cause severe psychological distress for the woman as well as disturbances in infant development. Infants of depressed mothers are at a higher risk for developmental delays, behavioral problems, and difficulty eating and sleeping. Moreover, new data indicate that prenatal depression also may adversely affect brain development of the child even before birth. Despite the high prevalence rates of prenatal depression and its negative consequences, few studies have tested the effectiveness of interpersonal psychotherapy IPT, a treatment for depression that focuses on interpersonal issues and relationships, during pregnancy. The administration of group prenatal IPT for depression may be effective in enhancing womens prenatal and postpartum moods and improving fetal and newborn functioning. This study will compare the effectiveness of group IPT with that of treatment as usual TAU for preventing postpartum depression in pregnant women with depression and for improving healthy outcomes in their babies. The study will also compare the fetal and newborn development of babies of healthy mothers with that of babies of depressed mothers. 