613: Intrapartum electronic fetal monitoring and the identification of neonates with hypoxic-ischemic encephalopathy treated with hypothermia protocol

Electronic fetal monitoring is the tool used to rapidly identify hypoxic-ischemic encephalopathy (HIE). We sought to determine how well the last hour of intrapartum monitoring prior to delivery can identify neonates meeting criteria for treatment with whole body cooling within 6 hours of birth. This is a case-control study of all 26 neonates born at 2 university hospitals between 1/1/07-7/1/11 treated with whole body cooling. Neonates treated with hypothermia were matched to the subsequent delivery by gestational age and mode of delivery. The last hour of fetal heart rate monitoring prior to delivery was read by 3 maternal-fetal medicine specialists using the 2008 NICHD guidelines and the readings averaged. Tracing parameters were compared using paired t tests and McNemara chi square. Assuming 3 +/− 3 late decelerations/hour for controls and alpha=0.05, a sample size of 16 patients in each group would have an 80% power to detect an increase to 6 late decelerations/hour in cases. Cases treated with hypothermia did not differ from controls in gestational age (39 +/− 1.7 vs. 39 +/− 1.6 weeks) or birth weight (3254 +/− 590 vs. 3082 +/−409 grams). The cesarean rate for both groups was 61.5%, and nonreassuring fetal heart rate tracing was noted as an indication for delivery in 87.5% of cases and 68.8% of controls. Neonates undergoing cooling had a significantly more acidotic cord pH (7.00 +/− 0.11 vs. 7.25 +/− 0.05, p<0.0001) and base deficit (13.7 +/− 4.8 vs. 3.4 +/− 2.4 mM, p<0.0001). Sentinel events included abruption in 1 (3.8%) and shoulder dystocia in 4 (15.4%) cases. The table demonstrates the tracing parameters and readings for cases and controls.Tabled 1 Review of the last hour of electronic fetal monitoring prior to delivery by 3 maternal-fetal medicine specialists using the 2008 NICHD guidelines was unable to distinguish neonates begun on hypothermia within 6 hours of birth. In this population with a high incidence of nonreassuring fetal heart rate tracings for both cases and controls only a significant decrease in early decelerations in the cases were found.