Effect of intrapartum oxygen on the rate of cesarean delivery: a meta-analysis: Condensation: Intrapartum oxygen administration does not change rate of cesarean delivery or other maternal or fetal outcomes.

BACKGROUND Maternal supplemental oxygen is often used intrapartum, with other fetal resuscitative maneuvers, for non-reassuring fetal heart rate monitoring (NRFHRM). OBJECTIVE To determine if maternal intrapartum administration of oxygen altered the rate of cesarean delivery (CD) when compared to room air. STUDY DESIGN This was a systematic review and meta-analysis of randomized controlled trials (RCTs). Searches were performed in MEDLINE, OVID, Scopus, ClinicalTrials.gov, and the Cochrane Central Register of Controlled Trials using a combination of keywords related to "pregnant patients," "labor," "oxygen," "fetus," "newborn," and pregnancy outcomes from database inception until April 2020. The study was registered with PROSPERO, registration number CRD42020162110. STUDY ELIGIBILITY CRITERIA Inclusion criteria were RCTs of maternal administration of oxygen compared to room air in labor. Exclusion criteria were quasi-randomized trials and oxygen administered for planned CDs. The primary outcome was rate of CD. Secondary maternal and neonatal outcomes including cord gas values were analyzed. STUDY APPRAISAL AND SYNTHESIS METHODS The Cochrane Handbook Guidelines were used to assess bias in trials. To calculate relative risk or mean differences with confidence intervals, a random-effects model was employed. Subgroup analyses were performed for women who received oxygen for non-reassuring fetal heart rate monitoring (NRFHRM) or prophylactically. RESULTS Five RCTs including 768 women were included in the meta-analysis, three using prophylactic oxygen and two using oxygen for NRFHRM. Risk of bias was generally considered low. There was no statistically significant difference between those given oxygen versus room air in rate of CD (16/365 (4.4%) vs. 11/379 (2.9%); risk ratio 1.5, 95% confidence interval 0.7-3.3). Additionally, there were no statistically significant differences in rates of CD for NRFHRM, operative vaginal deliveries, Apgar scores <7, neonatal intensive care unit admissions or cord blood gas values. There were no statistically significant differences when analyzing oxygen for NRFHRM alone or prophylactic oxygen alone. CONCLUSION Maternal intrapartum oxygen administration was not associated with any differences in the rate of CD or any secondary outcomes compared to room air overall as well as in the subgroups of therapeutic (for NRFHRM) or prophylactic administration in meta-analysis. Large RCTs are necessary to further examine any possible benefits or harms of oxygen administration in labor, particularly for NRFHRM.