Prenatal stress alters cytokine levels in a manner that may endanger human pregnancy

Objective: Recent data suggest that prenatal stress negatively affects pregnancy and infant outcome. Existing studies implicate dysregulation of the immune and endocrine systems in stress-related increases in premature labor and poor birth outcome, but no published studies have directly addressed the relationships among these variables during pregnancy. We sought to test the hypothesis that high levels of psychosocial stress and low levels of social support during pregnancy alter maternal cytokine profiles in a manner that contributes to poor birth outcomes. Methods: Psychosocial stress and social support were measured in 24 women with overtly normal pregnancies once during each trimester of pregnancy. Levels of interleukin-10 (IL-10), IL-6, and tumor necrosis factor-alpha (TNF-alpha) were assessed concurrently with stress and support measurements. Results: High social support was associated with low stress scores. Elevated stress scores were positively correlated with higher levels of the proinflammatory cytokines IL-6 and TNF-alpha, and with low levels of the antiinflammatory cytokine IL-10. Conclusions: These findings provide initial support for our hypothesis that stress-related neural immune interactions may contribute to pregnancy complications and poor outcome, but require further study to determine the mechanism and significance of these effects.