AbstractBackgroundThe aim of this study was to evaluate the relationship between umbilical cord blood interleukin (IL)‐6 concentration and preterm morbidity and mortality in premature infants born with fetal inflammatory response syndrome (FIRS).MethodsThis prospective, observational study included 84 preterm infants with a gestational age of 24–36 weeks who had been admitted to the neonatal intensive care unit (NICU). FIRS was defined as umbilical cord blood IL‐6 > 11 pg/mL. In premature infants with FIRS, morbidities (multiple organ failure [MOF], respiratory distress syndrome [RDS], patent ductus arteriosus, intraventricular hemorrhage, bronchopulmonary dysplasia, retinopathy of prematurity) and death were evaluated. Critical umbilical cord blood IL‐6 concentrations for the development of RDS, death, and for MOF were determined in premature infants with FIRS.ResultsFifty‐two infants with IL‐6 concentration > 11 pg/mL constituted the FIRS group. Thirty‐two infants without FIRS served as a control group. RDS, MOF, and mortality were significantly higher in the FIRS group (P = 0.001, P = 0.001, and P = 0.005, respectively). Umbilical cord blood IL‐6 concentration > 26.7 pg/mL in the FIRS group was found to be predictive of RDS, with 70% sensitivity and 85% specificity. Umbilical cord blood IL‐6 concentration > 37.7 pg/mL was found to be predictive of death, with 78.6% sensitivity and 60% specificity. The predictive value of IL‐6 for the development of MOF was 17.5 pg/mL, with 91% sensitivity and 66% specificity.ConclusionsUmbilical cord blood IL‐6 concentration > 26.7, 37.7, and 17.5 pg/mL in premature infants with FIRS was found to be predictive for RDS, death, and MOF, respectively.