Oxygen Saturation in Healthy Term Infants in The First Few Days of Life 

Objectives: Describe oxygen saturation (SpO 2 ) values and their variability in the newborn period for healthy term infants at moderate altitude. Methods: : Prospective observational study in postnatal wards with follow-up in the Public Health Nurse Clinic (PHNC). We recruited healthy term infants (≥37weeks) between 6-24 hours of age. Infants underwent simultaneous pre- (90mins) and post-ductal (10mins) transcutaneous SpO 2 recordings every 12-24 hours until hospital discharge. Simultaneous pre- and post-ductal SpO 2 measurements (15mins) were performed again in the PHNC within a few days after discharge. Infants were followed for eight weeks to ascertain their health status. Results: : We included 252 infants with a complete in-hospital data set. Median age at the time of first SpO 2 measurement in the hospital was 16.5 h, and 65.7 h in the PHNC (n=105). In hospital, the mean pre- and post-ductal SpO 2 were 94.3% (SD 2.5) and 96.0% (SD 3.0), respectively. In the PHNC, mean pre- and post-ductal SpO 2 were 94.4% (SD 2.8) and 95.6% (SD 2.7), respectively. Preductal desaturation episodes to SpO 2 <95% were more frequent in the PHNC than in the hospital (rate ratio 1.27, P=0.02). The median durations of preductal desaturation episodes were longer in hospital than in the PHNC (range 9 to 20 seconds longer) for all pre ductal SpO 2 thresholds examined (P<0.05). Conclusion: SpO2 levels in healthy term newborns are approximately 94% over the first few days after birth at moderate altitude. Desaturation episodes are common in the immediate newborn period, but the duration of desaturation episodes decreases over time.