Is it a safe practice to administer oxygen during uncomplicated delivery: a randomized controlled trial?

Background: Newborns exposed to oxygen suffer from an oxidative stress with significant alterations in the concentrations of superoxide dismutase (SOD) and glutathione (GSSG).

Objective: To investigate the biological and clinical effects of oxygen administration to delivering mothers.

Methods: We conducted a randomized, double-blinded, controlled trial on a cohort of delivering women (n=56) with an uncomplicated term pregnancy. Women were randomly assigned to one of two groups: Oxygen group or Room Air group. The Oxygen group received 100% oxygen (2l/min) via nasal cannula for at least 30 min before delivery. Subjects in the Room Air group were connected to a nasal cannula while on room air. Concentrations of SOD (μg/g of Hb) and GSSG (μM/ml) were measured in maternal and umbilical cord blood. Bivariate and multivariate analyses were used to compare the two groups using the SAS system.

Results: Maternal SOD and GSSG did not differ between the two groups at baseline or after delivery. Concentrations of SOD and GSSG in umbilical cord blood did not differ between groups. More infants in Oxygen Group required delivery room resuscitation (20% vs. 0%, P=0.03). This difference could not be explained by mode of delivery, infant sex, or other confounders.

Conclusions: Maternal exposure to oxygen during delivery is not associated with changes in umbilical cord SOD or GSSG. Further studies are needed to explore mechanisms responsible for the need of resuscitation in the oxygen group.