Complications related to preterm birth (PTB) and low birth weight (LBW) are leading causes of infant morbidity and mortality. Prenatal depression is a hypothesized psychosocial risk factor for both birth outcomes. The purpose of this systematic review was to examine evidence published between 1977 and 2013 on prenatal depression and risks of these primary adverse birth outcomes. A systematic search of the PUBMED and PsycINFO databases was conducted to identify studies testing the associations between prenatal depressive symptoms, or diagnoses of depression, and risk of PTB or LBW. We systematically selected 50 published reports on PTB and length of gestation, and 33 reports on LBW and BW. Results were reviewed by two independent reviewers and we evaluated the quality of the evidence with an established systematic review method, the Newcastle Ottawa Scale. We then undertook a narrative synthesis of the results following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Less than a quarter of 50 published reports found that prenatal depression was significantly associated with PTB or gestational age. In contrast, slightly more than half of the 33 reports found that prenatal depression was associated with LBW or BW. When weighing methodological features, we determined that the effects of prenatal depression on LBW are more consistent than effects on length of gestation or PTB. Although the evidence may not be strong enough to support routine depression screening for risk of adverse outcomes, screening to enable detection and timely treatment to reduce risk of postpartum depression is warranted. Further rigorous research on prenatal depression and adverse birth outcomes is needed.

Purpose Vitamin D deficiency and elevated pro-inflammatory cytokines have been associated individually with postpartum depression (PPD). African American women are at increased risk for prenatal vitamin D deficiency, inflammation, and prenatal and postpartum depressive symptoms, but biological risk factors for PPD in this population have rarely been tested. This prospective study tested whether low prenatal vitamin D status (serum 25-hydroxyvitamin D, 25[OH]D) predicted PPD symptomatology in pregnant African American women, and whether high levels of prenatal inflammation interacted with low 25(OH)D in effects on PPD symptoms. Methods Vitamin D status was measured in the first trimester in a sample of 91 African American pregnant women who also had a second trimester blood sample assayed for inflammatory markers. Depressive symptoms were assessed at a postpartum visit. Results An inverse association between prenatal log 25(OH)D and PPD symptomatology approached significance (β = -0.209, p = 0.058), and interleukin-6 and IL-6/IL-10 ratio significantly moderated the effect. Among women with higher levels of inflammatory markers, lower prenatal log 25(OH)D was associated with significantly higher PPD symptoms (p <0.05). Conclusion These preliminary results are intriguing because if replicable, simple translational opportunities, such as increasing vitamin D status in pregnant women with elevated pro-inflammatory cytokines, may reduce PPD symptoms.

High-quality prenatal care systems should develop the capacity for depression and anxiety risk assessment and treatment. Providers should routinely screen using validated screening tools, provide maternal mental health education, and be aware of the various medical, psychological, and complementary approaches for treating mood and anxiety disorders, to best guide and refer patients. The use of this practice will increase the quality of life in pregnant women with depression and anxiety and may help to reduce the likelihood of adverse birth outcomes, postpartum mental health problems, and adverse effects on offspring.

To effectively treat MDD in women and to prevent the recurrence of illness in vulnerable women, clinicians must understand the sex-specific aspects of mood disorders over the longitudinal course of women's reproductive lives. A biopsychosocial approach should, therefore, be the main focus of future research and practice, to eventually result in an integrated etiological model of depression in women. Based on the prevalence of MDD in women, timely screening, diagnosis, and intervention should be public health priorities.