Perinatal Outcome Following the Suspension of Intrapartum Oxygen Treatment.

Objective To evaluate whether the suspension of intrapartum maternal oxygen supplementation for non-reassuring 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 16/4/2020, 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 seven months between 16/4/2020 and 14/11/2020. The control group included individuals that underwent labor during the seven months before 16/4/2020. 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 4932 individuals, compared to 4906 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%), p<0.001], including the rate of abnormal cord arterial pH <7.1 [119 (2.4%) vs. 56 (1.1%), p<0.01]. A higher rate of cesarean section due to non-reassuring fetal heart rate was noted in the study group [320 (6.5%) vs. 268 (5.5%), p=0.03]. A logistic regression analysis revealed that the suspension of intrapartum oxygen treatment was independently associated with the composite neonatal outcome [aOR 1.60 (95% CI, 1.26-2.01)] while adjusting for labor induction, oxytocin administration, epidural analgesia, and presence of meconium-stained fluid. Conclusions Suspension of intrapartum oxygen treatment for non-reassuring fetal heart rate was associated with higher rates of adverse neonatal outcomes and urgent cesarean section due to fetal heart rate.