Does maternal oxygen administration during non-reassuring fetal status affect the umbilical artery gas measures and neonatal outcomes?

Abstract

Abstract Purpose: To clarify whether maternal oxygen administration during vaginal delivery improves umbilical artery (UA) gas measurements and neonatal outcomes. Methods: Singleton pregnancies requiring operative vaginal delivery or emergency cesarean section (CS) due to non-reassuring fetal status (NRFS) during vaginal delivery at our hospital from 2018 to 2021 were retrospectively investigated. Intrapartum fetal wellbeing was evaluated based on the 5-tier fetal heart rate (FHR) pattern which is a delivery management method widely used in Japan. Operative vaginal deliveries or emergency CS were performed under integrated judgment in NRFS. Patients were divided into the oxygen group in which oxygen (10 L/min) was supplied by a facemask and the room air group. The umbilical artery (UA) gas measurements and neonatal outcomes were compared retrospectively. The oxygen administration was classified by conditions before and after the Coronavirus Disease 2019 pandemic. As a secondary evaluation, stratification of FHR pattern levels was also examined. Results: A total of 250 patients required obstetric surgical delivery due to NRFS, including 140 (56%) and 110 (44%) in the oxygen and room air groups, respectively. No differences in maternal background factors were found between the oxygen and room air groups, except for maternal age. UA gas measurements and neonatal outcomes also showed no significant differences. Conclusions: Transmaternal oxygen administration for intrapartum NRFS did not affect neonatal cord blood gases and neonatal outcomes. Thus, routine oxygen administration for intrapartum NRFS may not always be necessary.