Oxygen Saturation Ranges for Healthy Newborns within 2 h at Altitudes between 847 and 4,360 m: A Prospective Cohort Study

Abstract

<b><i>Introduction:</i></b> The partial oxygen pressure in the air decreases with increasing altitude. This study was designed to compare the pulse oxygen saturation (SpO₂) among well full-term neonates at different altitudes during their first 2 h after birth and to establish cutoff values of SpO₂ identifying hypoxemia between 30 and 120 min after birth. <b><i>Methods:</i></b> A multisite prospective cohort study was conducted at five participating hospitals from the Chinese High Altitude Neonatal Medicine Alliance. Healthy full-term infants were recruited and divided into four groups based on the altitude. Preductal SpO₂ was recorded at 10 min, 10–30 min, and 30–120 min after birth. The 2.5th percentile of the SpO₂ distribution range was considered as the cutoff for identifying hypoxemia at each altitude. <b><i>Results:</i></b> A total of 727 infants were eligible for analysis. The SpO₂ of neonates at different altitudes increased with the time after birth. A higher altitude was associated with lower SpO₂, especially Shangri-La (3,509 m) and Yushu (4,360 m). The cutoff SpO₂ for identifying hypoxemia during 30–120 min after birth were 94% in Xishuangbanna (847 m), 92% in Kunming (1,983 m), 89% in Shangri-La (3,509 m), and 83% in Yushu (4,360 m). <b><i>Conclusion:</i></b> An increase in altitude, especially Shangri-La (3,509 m) and Yushu (4,360 m), had a significant impact on SpO₂ among healthy full-term neonates during their first 2 h of life. Establishing the cutoff value of SpO₂ for identifying hypoxemia during the early postnatal period serves to optimize the oxygen therapy at different altitudes.