Elevation of interleukin-6 levels in cervical secretions as a predictor of preterm delivery

BACKGROUND: The objective of this study was to evaluate the predictive value of interleukin-6 (IL-6) in cervical secretions for preterm delivery before 34+0 gestational weeks in patients with preterm labor. METHODS: In this prospective study, 31 patients were enrolled with preterm labor and intact membranes. Cervical swabs were taken on admission and the concentration of IL-6 was measured. The gestational age at the time of admission and delivery, as well as the time interval to delivery, were evaluated and compared with the concentration of IL-6 on admission. RESULTS: Cervical IL-6 was significantly elevated in the preterm delivery group (< 34+0 gestational weeks, p < 0.05). Choosing 20 pg/ml as a cut-off concentration, cervical IL-6 had a sensitivity and negative predictive value of 100%, a specificity of 67% and a positive predictive value of 47%. Concerning the time interval to delivery, the sensitivity of IL-6 was 100% and the specificity 57% for delivery within 2 days and 100% and 64% for delivery within 7 days. CONCLUSIONS: Cervical IL-6 is a new, promising diagnostic tool to identify patients at high risk of preterm delivery.