Electronic Fetal Monitoring Predicts Severe Fetal Acidemia (Umbilical Cord Arterial pH [25D

Abstract

INTRODUCTION: The purpose of this study was to determine how frequently intrapartum electronic fetal monitoring (EFM) was interpreted as concerning, with delivery expedited, in babies with severe acidemia (umbilical cord arterial pH < 7). METHODS: A retrospective cohort study was performed on babies with umbilical cord arterial pH < 7. Two groups were identified: (1) expedited delivery (either operative vaginal delivery or urgent/emergent cesarean section) and (2) non-expedited delivery (spontaneous vaginal delivery, scheduled or non-urgent cesarean section). Maternal, labor, and neonatal characteristics between the groups were compared using Chi-squared test for independence and the Fisher’s Exact Test. RESULTS: 30 babies were identified with umbilical cord arterial pH < 7. 47% were delivered in expedited fashion. 53% were delivered in non-expedited fashion. Of the expedited delivery group, 79% were delivered by cesarean section and 21% by operative vaginal delivery. Of the non-expedited delivery group, 56% were delivered by cesarean section (scheduled or non-urgent). There was no statistical difference between groups in average umbilical cord arterial pH or base excess, gestational age, if labor was induced, length of labor, Pitocin usage for labor augmentation, sentinel events, 5 minute Apgar score or neonatal length of stay. CONCLUSION: Only 47% of babies with umbilical cord arterial pH of < 7 delivered in expedited fashion. There was no statistical difference in maternal, labor or neonatal characteristics between the expedited and non-expedited delivery groups. Poor sensitivity of EFM in predicting intrapartum hypoxia and acidemia limits the ability to expedite delivery in the presence of fetal acidemia.