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 inf ectious complications in patients with preterm premature rupture of membran es. 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 immunoadsor bent assay (ELISA) using 50 mL of plasma assayed in duplicate. ELISA sensit ivity was 18 pg/mL. Neonatal and infectious complications examined were res piratory distress syndrome, necrotizing enterocolitis, intraventricular hem orrhage, intra-amniotic infection, presumed neonatal sepsis, neonatal sepsi s, and congenital pneumonia. Fifty-seven patients' plasma was analyzed. Thi rty-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 recei ved a course of corticosteroids was performed and significance was maintain ed. Ten of 13 patients (77%) with neonatal complications had positive IL-6 compared with 40% without complications (p less than or equal to 0.01). Inf ectious morbidity occurred in 32 patients with 24 having positive IL-6 valu es (75%). Only 11 of 25 (44%) without infections were positive (p less than or equal to 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 corr elations persisted when the data were stratified for those patients who rec eived corticosteroids. It also predicted infectious complications.