Depression is a serious illness that affects a person's body, mood, and thoughts. Researchers believe that it is one of the most common complications during and after pregnancy. The following symptoms may be signs of depression during pregnancy: 2 or more weeks of depressed mood; decreased interest or pleasure in activities; change in appetite or sleep patterns; fatigue or decreased energy; difficulty concentrating; excessive feelings of guilt or worthlessness; thoughts of suicide; and extreme restlessness or irritability. Depression is difficult to diagnose during pregnancy because its symptoms are sometimes confused with those of pregnancy. If left untreated, depression during pregnancy may affect not only the mother, but also the baby. Specifically, the hormone changes brought on by depression may contribute to premature and low-birth-weight infants. Interpersonal psychotherapy (IPT) is a short-term talking therapy that has been proven to be effective in treating depression. This study will evaluate the impact of interpersonal psychotherapy on the course of depression during and after pregnancy, as well as its effect on infant birth outcomes.