Temporal and Quantitative Associations of Electronic Fetal Monitoring with Outcomes [12N

Abstract

INTRODUCTION: To evaluate the use of intrapartum electronic fetal heart rate (FHR) monitoring (EFM) as a screening tool for adverse neonatal outcomes METHODS: This is a retrospective study of 22,126 term, singleton deliveries excluding repeat cesarean sections at a hospital system from 2013-2016. EFM data using standardized NICHD nomenclature was reviewed. Data was analyzed as discrete, quantitative, and tabulated as a) any FHR documentation during labor, b) first 60 minutes and c) last 60 minutes of labor. Primary outcome was a composite adverse outcome comprised of five-minute Apgar score < 4, umbilical arterial pH < 7.0, sepsis, seizures, encephalopathy, and respiratory failure. Secondary outcome was NICU admission. Independent associations were ascertained using logistic regression. Sensitivity, specificity, PPV and NPV were calculated. RESULTS: Any abnormal EFM was independently significantly associated with NICU (aOR=1.20 p=0.043) and primary outcome (aOR=1.98 p=0.018). Both first and last 60 minutes had independent associations with NICU. Last 60 minutes but not first 60 minutes was independently associated with the primary outcome, Accelerations and early decelerations were protective against NICU admissions and primary outcomes, while late and prolonged decelerations, bradycardia and tachycardia increased risk for both (Table). Negative predictive values for all EFM parameters ranged from 0.897-0.989 while the PPV ranged from 0.009-0.226. CONCLUSION: Both admission and terminal FHR are independently associated with NICU admissions but only terminal FHR is predictive of composite neonatal outcome. Accelerations and early decelerations are protective of adverse neonatal outcomes. FHR has high NPV but low PPV when used as screening for adverse neonatal outcomes.