Second trimester maternal plasma levels of cytokines IL-1Ra, Il-6 and IL-10 and preterm birth.

OBJECTIVE: To examine the interaction of the cytokines interleukin-1 receptor antagonist (IL)-1Ra, IL-6 and IL-10 to predict preterm birth (PTB) in pregnant Hispanic women (n=470). STUDY DESIGN: In this prospective study, demographic data were obtained prenatally and birth outcome data were obtained from the medical chart. Cytokines were measured from plasma obtained at 22 to 24 weeks gestation. Data analysis utilized logistic regression. RESULT: PTB was predicted by level of IL-1Ra (odds ratio (OR)=2.55; 95% confidence interval (CI)=1.24, 5.24). The interaction between IL-1Ra and IL-6 and between IL-1Ra and IL-10 was significant (Wald=4.01, P=0.04 and Wald=8.84, P<0.003, respectively) and was also predictive of PTB. As IL-1Ra levels increased while IL-10 levels were low, the probability of PTB greatly increased. CONCLUSION: The interactions of select cytokines and cytokine receptor antagonists were associated with PTB. Future research should focus on the changes in cytokines during pregnancy to identify critical periods of change, and examine predictors of the cytokine response.