Deimplementation of Routine Maternal Oxygen Supplementation for Intrauterine Fetal Resuscitation: A Retrospective Cohort Study.

Objective:  Current practice guidelines for laboring patients with category II intrapartum tracings recommend maternal oxygen supplementation despite emerging randomized data challenging its benefit and utility. We aim to validate that de-implementing maternal oxygen supplementation for fetal resuscitation did not increase the risk of neonatal acidemia in a real-world setting.

Study design:  This is a retrospective observational study conducted at a single tertiary care center from January 2019 to June 2021. All laboring deliveries during the study period were reviewed and eligible participants included singleton or twin pregnancies between 23 and 42 weeks gestational age with persistent category II tracings. Known major fetal anomalies, contraindications to labor, and maternal indication for O₂ supplementation, including active coronavirus disease 2019, were excluded. Cohorts were allocated based on the time of delivery. Those occurring prior to our hospital policy change were identified as historical controls and deliveries after April 1, 2020, as the postdeimplementation cohort. The primary outcome was fetal acidemia, defined as umbilical cord pH < 7.2. Secondary outcomes included severe acidemia (pH < 7.0), 5-minute Apgar score <4, and neonatal intensive care admission. Regression analyses controlling for known variables associated with neonatal acidemia generated adjusted odds ratios (aORs) with 95% confidence intervals (CIs).

Results:  Among 9,088 deliveries during the study period, 1,162 tracings were flagged as persistent category II, including 681 (59%) in the postintervention group. The two cohorts had comparable baseline and obstetric characteristics. No difference in neonatal acidemia was observed between the postdeimplementation group and historical controls (13.8 vs. 15.4%, aOR = 0.87, 95% CI: 0.62, 1.22). Severe acidemia, 5-minute Apgar <4, and neonatal intensive care admission were not increased in the postdeimplementation group.

Conclusion:  De-implementation of routine maternal oxygen supplementation for fetal resuscitation did not increase the likelihood of neonatal acidemia in a real-world setting, validating guidelines recommending against the intervention.

Key points: · De-implementation of maternal O2 supplementation for fetal resuscitation did not increase acidemia.. · Real-world experience validates experimental findings regarding maternal oxygenation.. · Other perinatal outcomes reflected no difference in fetal acidemia..