Supplemental Oxygen Study: A Randomized Controlled Study on the Effect of Maternal Oxygen Supplementation during Planned Cesarean Delivery on Umbilical Cord Gases.

OBJECTIVE:  The aim was to determine the fetal umbilical blood gas effects of supplemental maternal oxygenation compared with room air (RA) during term planned cesarean delivery.

METHODS:  This is a prospective randomized controlled study of singleton planned cesarean deliveries randomized to receive supplemental oxygen (O2 ) at 10 L per minute (L/min) via facemask or RA. Umbilical cord gases were collected. The primary outcome was umbilical arterial pH level. Secondary outcomes included umbilical cord values and maternal and neonatal outcomes. Data were expressed as median ± interquartile range (IQR).

RESULTS:  Seventy subjects in total were enrolled, with 65 subjects available for analysis. The median umbilical arterial p O2 was significantly increased in the supplemental O2 group (18 [13.5-20.5] mm Hg) versus RA group (16 [12-18] mm Hg), p  = 0.04). The median umbilical venous p O2 was significantly increased in the supplemental O2 group (32 [26.5-36.0] mm Hg) versus RA group (28.5 [22-34.3] mm Hg), p  = 0.04). There were no significant differences with other umbilical blood gas values and composite maternal or neonatal complications.

CONCLUSION:  Subjects with term singleton gestations receiving O2 at 10 L/min during cesarean delivery compared with RA demonstrated no significant change in umbilical cord pH values. There was a significant increase in umbilical cord arterial and venous O2 levels in those receiving O2 .