Perinatal Outcome following the Suspension of Intrapartum Oxygen Treatment.

OBJECTIVE

This study aimed to evaluate whether the suspension of intrapartum maternal oxygen supplementation for nonreassuring fetal heart rate is associated with adverse perinatal outcomes.

STUDY DESIGN

A retrospective cohort study, including all individuals that underwent labor in a single tertiary medical center. On April 16, 2020, the routine use of intrapartum oxygen for category II and III fetal heart rate tracings was suspended. The study group included individuals with singleton pregnancies that underwent labor during the 7 months between April 16, 2020, and November 14, 2020. The control group included individuals that underwent labor during the 7 months before April 16, 2020. Exclusion criteria included elective cesarean section, multifetal pregnancy, fetal death, and maternal oxygen saturation <95% during delivery. The primary outcome was defined as the rate of composite neonatal outcome, consisting of arterial cord pH <7.1, mechanical ventilation, respiratory distress syndrome, necrotizing enterocolitis, intraventricular hemorrhage grade 3/4, and neonatal death. The secondary outcome was the rate of cesarean and operative delivery.

RESULTS

The study group included 4,932 individuals, compared with 4,906 individuals in the control group. The suspension of intrapartum oxygen treatment was associated with a significant increase in the rate of composite neonatal outcome (187 [3.8%] vs. 120 [2.4%],  < 0.001), including the rate of abnormal cord arterial pH <7.1 (119 [2.4%] vs. 56 [1.1%],  < 0.01). A higher rate of cesarean section due to nonreassuring fetal heart rate was noted in the study group (320 [6.5%] vs. 268 [5.5%],  = 0.03).A logistic regression analysis revealed that the suspension of intrapartum oxygen treatment was independently associated with the composite neonatal outcome (adjusted odds ratio = 1.55 [95% confidence interval, 1.23-1.96]) while adjusting for suspected chorioamnionitis, intrauterine growth restriction, and recent coronavirus disease 2019 exposure.

CONCLUSION

Suspension of intrapartum oxygen treatment for nonreassuring fetal heart rate was associated with higher rates of adverse neonatal outcomes and urgent cesarean section due to fetal heart rate.

KEY POINTS

· The available data on intrapartum maternal oxygen supplementation are equivocal.. · Suspension of maternal oxygen for nonreassuring fetal heart rate during labor was associated with adverse neonatal outcomes.. · Oxygen treatment might still be important and relevant during labor..