The influence of labor and gestational age on maternal IL-6 and IL-10 plasma levels in preeclampsia.

Preeclampsia and labor are associated with pro-inflammatory responses, but differences in cytokine profiles might reflect distinct immunological pathways. This study investigates maternal cytokine profiles in relation to preeclampsia and status of labor to explore shared and distinct inflammatory mechanisms involved in the onset and progression of both. Maternal blood plasma samples were collected from 93 women in the third trimester; 44 with preeclampsia and 49 healthy controls. Concentrations of IL-2, IL-4, IL-5, IL-6, IL-10, IL-17A, IFN-α2a, IFN-β, IFN-γ, and TNF-α were measured using multiplex immunoassay, of which IL-6, IL-10, IFN-γ and TNF-α were reliably detected. TNF-α was detected more frequently in women with preeclampsia, and IL-10 was associated with reduced odds of preeclampsia in unadjusted analyses, though these associations were not significant after adjustment. IL-6 and IL-10 levels were significantly higher in women included close to labor, regardless of preeclampsia status, and both cytokines showed a strong inverse correlation with time to delivery. Maternal cytokine levels were modulated by both preeclampsia and labor status. While no cytokines were significantly associated with preeclampsia after adjustment, TNF-α and IL-10 showed trends toward differential expression. IL-6 and IL-10 increased significantly close to labor, highlighting the importance of labor timing when interpreting inflammatory markers in pregnancy.