L.Tungalag^1*, Z.Gerelmaa²

¹ Third Maternity hospital

² School of Medicine, Health Sciences University of Mongolia

To study the normal levels of oxygen saturation (saturation by pulse oximetry, SpO₂) in healthy newborns during the first 10 minutes of life and the possible relationship to birth weight or mode of delivery.  In this observational study, asymptomatic newborns with gestational age ≥37 weeks at birth that did not require supplemental oxygen had continuous recordings taken of the postductal oxygen saturation over the first 10 minutes of life. A total 132 deliveries were monitored. Oxygen saturation readings were obtained 1, 5, 10 minutes of life. The median oxygen saturation at 1 minute was 64%, at 5 minutes 83%, at 10 minutes 97%. Oxygen saturation was significantly related to mode of delivery. Infants delivered by cesarean delivery had 1.5% lower oxygen saturation than in those delivered vaginally. (95% confidence interval, P<0.001).No relationship exists between oxygen saturation and birth weight. In healthy newborns, levels oxygen saturation measured during the first 10 minutes of life are negatively related to birth weight and related to mode of delivery. The process of transitioning to normal postnatal oxygen saturation requires more than 5 minutes in healthy newborns breathing room air.