Maternal serum interleukin-6 levels predict impending funisitis in preterm premature rupture of membranes after completion of antibiotics

OBJECTIVE: To determine if maternal serum interleukin-6 (IL-6) levels remain predictive of funisitis after completion of antibiotic administration in preterm premature rupture of membranes (PPROM). METHODS: A secondary analysis of a prospective cohort study. Daily blood samples obtained from PPROM subjects were analyzed for IL-6 by enzyme-linked immunosorbent assay. Subjects (N = 39) delivered >7 days post admission and were divided into those with and without funisitis. Data were analyzed using Mann-Whitney U test. RESULTS: Maternal serum IL-6 levels obtained 24-48 hours and 48-72 hours before delivery are elevated in PPROM subjects with funisitis compared to those without funisitis (6.3 vs. 2.7 pg/ml, P < 0.03; 6.1 vs. 1.7 pg/ml, P < 0.02). Receiver operator characteristic curve revealed an IL-6 level of 1.98 pg/ml had sensitivity of 86.7%, specificity of 46.7%, positive predictive value of 61.9% and negative predictive value of 77.8%. CONCLUSION: This data suggests that maternal serum IL-6 levels continue to be predictive of PPROM subjects destined to develop funisitis after completion of antibiotics.