Detection of interleukin-6 in maternal plasma predicts neonatal and infectious complications in preterm premature rupture of membranes.

The objective of this study is to determine if the detection of interleukin-6 (IL-6) in maternal plasma prior to delivery predicts neonatal and/or infectious complications in patients with preterm premature rupture of membranes. Patients with preterm premature rupture of membranes between 24 and 35 weeks' gestation were asked to participate in the study. Maternal blood was obtained prior to delivery. All patients received Ampicillin-sulbactam and steroids. IL-6 concentrations were determined by enzyme-linked immunoadsorbent assay (ELISA) using 50 mL of plasma assayed in duplicate. ELISA sensitivity was 18 pg/mL. Neonatal and infectious complications examined were respiratory distress syndrome, necrotizing enterocolitis, intraventricular hemorrhage, intra-amniotic infection, presumed neonatal sepsis, neonatal sepsis, and congenital pneumonia. Fifty-seven patients' plasma was analyzed. Thirty-five had positive plasma IL-6 prior to delivery. Twenty-seven patients had at least one neonatal complication with 24 (89%) being positive for IL-6. Of the 30 patients without complications, only 11 (37%) were positive (p = 0.0001, OR 13.8. 95% CI, 2.93-74.7). A subanalysis of patients who received a course of corticosteroids was performed and significance was maintained. Ten of 13 patients (77%) with neonatal complications had positive IL-6 compared with 40% without complications (p <or=0.01). Infectious morbidity occurred in 32 patients with 24 having positive IL-6 values (75%). Only 11 of 25 (44%) without infections were positive (p <or=0.03, OR 3.82, 95%, CI 1.09-13.0). The presence of IL-6 in the maternal plasma predicted patients with neonatal complications. These correlations persisted when the data were stratified for those patients who received corticosteroids. It also predicted infectious complications.