Purpose: This study examined the associations among maternal depression, measured in several ways, psychiatric medication use in pregnancy, and preterm delivery (PTD).
Methods: Data were collected from 3,019 women enrolled in the Pregnancy Outcomes and Community Health Study (1998-2004), a prospective study of pregnant women in five Michigan communities. Information on depressive symptoms, history of depression, and psychiatric medication use was ascertained through interviews at mid-pregnancy. These variables and other relevant covariates were incorporated into regression models with a binary outcome, that is, term (> or =37 weeks' gestation) as referent and PTD (<37 weeks' gestation). A second set of models used a multicategory outcome, namely, term as the referent and PTD further subdivided by gestational weeks and clinical circumstances.
Main findings: The odds of overall PTD was increased among women who used psychiatric medication during pregnancy and had either elevated levels of depressive symptoms at mid-pregnancy (adjusted odds ratio [AOR], 2.0; 95% confidence interval [CI], 1.1-3.6) or a history of depression before pregnancy (AOR, 1.6; 95% CI, 1.1-2.5). The combination of psychiatric medication use in pregnancy and depression, before pregnancy, or within pregnancy was most strongly linked to a medically indicated delivery before 35 weeks' gestation (AOR, 2.9 and 3.6, respectively).
Conclusions: There are at least two plausible explanations for these findings. First, psychiatric medication use in pregnancy may pose an excess risk of PTD. Second, medication use may be an indicator of depressive symptom severity, which is a direct or indirect (i.e., alters behavior) contributing factor to PTD.