Researchers analyzed responses of nearly 3,020 women who participated in the Michigan-based Pregnancy Outcomes and Community Health Study, which asked about depressive symptoms that occurred within the week of taking the questionnaire. The study also asked about the women's history of depression that required medication, such as tranquilizers or sleeping pills.

Overall, 335 women (11 percent) delivered preterm. Among the women who reported having depression during pregnancy, 75 percent had a history of depression and 62 percent used medication in the first half of pregnancy.

Another finding showed that without medication use, elevated levels of depressive symptoms at midpregnancy and history of depression did not pose an increased risk of preterm delivery.

The study's other researchers include Claudia Holzman, professor of epidemiology at Michigan State, and Yan Tian, a data analyst at Michigan State.

The findings appear in the September/October issue of Women's Health Issues. Funding came from the National Center for Research Resources, the National Institute of Child Health and Human Development, the National Institute of Nursing Research, the March of Dimes Foundation and the Centers for Disease Control and Prevention.

Source: University of Washington