Antenatal Depression and Preterm Delivery: A Prospective Cohort Study

Background: This study examines whether antenatal major depression increases the risk of delivering subsequent preterm infants (< 37 weeks completed gestation). High rates of depression in women are a global phenomenon, with the World Health Organization declaring major depressive disorder the leading cause of disease-related disability among women worldwide (Annals of Tropical Medicine Parasitology 2006;100:481-499). The median age of onset for major depression occurs during the childbearing years, which contributes to major depression being a frequent medical disorder during pregnancy. Our understanding of the influence of antenatal depression on preterm delivery is currently deficient. The vast majority of U.S. studies of antenatal depression and prematurity have assessed depressive symptoms, however, instead of providing information about depressive disorders. This distinction is important, since depressive disorders are unlikely to remit without treatment – thus diagnosing and treating antenatal depression is vital due to sequelae of untreated depression, which has adverse consequences in the antepartum (i.e., substance use, poor weight gain, inadequate prenatal care) which may affect outcomes in the peripartum (i.e., preterm delivery).

Methods: We performed a longitudinal analysis of data from an ongoing registry. Study participants were 2,577 women receiving prenatal care at a university obstetric clinic from January 2004 through March 2010. Logistic regression models were specified to examine the effect of antenatal major depression on offspring gestational age at birth unadjusted and adjusted for sociodemographic, behavioral, obstetric, and psychological factors. Antenatal depression was assessed using the Patient Health Questionnaire, which yields diagnoses for major depression, minor depression, and panic disorder using DSM-IV criteria.

Results: Analyses revealed antenatal depression (both minor and major) predicted an increased risk of preterm delivery (OR = 1.48; 95% CI: 1.04 – 2.10). Additional predictors of preterm delivery included antenatal smoking (OR = 1.66; 95% CI: 1.11-2.47), and 2 or more antenatal medical problems (OR = 2.18; 95% CI: 1.67 – 2.85).

Conclusions and Implications: Women with antenatal depression are at increased risk to delivery premature infants. Our findings highlight the importance of screening and treatment of antenatal depression in an effort to reduce the burden of prematurity.