Depressive symptoms are associated with elevated serum proinflammatory cytokines among pregnant women

Psychosocial stress and depressive symptoms are associated with increased risk of negative perinatal outcomes including preterm delivery and gestational hypertension. Inflammation is a likely mechanism by which distress may promote these outcomes. It is well-established that stress and depressive symptoms are associated with elevated serum inflammatory markers in nonpregnant populations. However, the immune system exhibits significant changes during pregnancy. Thus, the extent to which these findings extend to pregnancy is largely unknown. The current study examined associations among perceived stress, depressive symptoms, and serum inflammatory markers in a sample of 60 pregnant women. Fifty seven percent were African-American, 82% had completed high school or less education, and 63% reported an annual family income below $15,000. Participants completed the Perceived Stress Scale (PSS) and the Center for Epidemiologic Studies Depression Scale (CES-D). Serum levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) were determined using high sensitivity immunoassays. Regression analyses demonstrated that after controlling for pre-pregnancy Body Mass Index (BMI), higher scores on the CES-D were related to significantly higher levels of IL-6 (beta=.23, p=.05) and marginally higher TNF-alpha (beta=.24, p=.06). Perceived stress was not significantly related to serum levels of IL-6 or TNF-alpha. In sum, these results indicate that depressive symptoms are associated with higher levels of maternal serum inflammatory markers during pregnancy. These data are consistent with the contention that depressive symptoms may contribute to negative perinatal outcomes via inflammatory pathways.