Pregnant women with a history of depression who used psychiatric medication are at higher risk of premature child delivery, say researchers at the University of Washington, University of Michigan and Michigan State University.
Their study showed that a combination of medication use and depression - either before or during pregnancy - was strongly linked to delivery before 35 weeks' gestation.
Amelia Gavin, lead author and UW assistant professor of social work, said the findings highlight the need for carefully planned studies that can clarify associations between depression, psychiatric medications and preterm delivery.
"Women with depression face difficult decisions regarding the benefits and risks of using psychotropic medications in pregnancy. Therefore, a focus on disentangling medication effects and depression effects on mother and offspring health should be a major clinical priority," Gavin said.
Kristine Siefert, co-author and a Michigan professor of social work, said:Medication use may be an indicator of depressive symptom severity, which is a direct or indirect contributing factor to pre-term delivery."
Most physicians initiated preterm deliveries after the women suffered complications, such as pre-eclampsia, poor fetal growth or acute hemorrhage.
The study examined the associations among maternal depression, psychiatric medication use in pregnancy and preterm delivery among women in five Michigan communities who received prenatal care at one of 52 participating clinics between September 1998 and June 2004.
These women had to be at least 15 years old, with no history of diabetes, and were 15 to 27 weeks pregnant.
Researchers analyzed responses of nearly 3,020 women who participated in the Michigan-based Pregnancy Outcomes and ommunity 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.
The study also 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.