[The distribution and variance of neonatal pulse oxygen saturation at different altitudes]

Objective: To analyze the distribution and variance of neonatal pulse oxygen saturation (SpO₂) at different altitudes in China, and provide a new evidence for the screening of NCHD at high altitudes. Methods: Based on the database of National Screening Project of NCHD, the distribution of SpO₂ values was described in 26 766 newborns at altitudes of 0-100 m, 600-700 m, 900-1 100 m, 1 400-1 600 m, 1 900-2 100 m, and 2 200-2 500 m. One-way analysis of variance was used to analyze the differences among SpO₂ values in newborns at different altitudes. Results: The average SpO₂ values of right hand in newborns at altitudes of 0-100 m, 600-700 m, 900-1 100 m, 1 400-1 600 m, 1 900-2 100 m and 2 200-2 500 m were 97.7%±1.4%, 97.1%±1.1%, 96.1%±1.3%, 96.0%±1.7%, 95.9%±1.7% and 95.5%±2.4%, respectively. And corresponding average SpO₂ values of either foot were 97.7%±1.4%, 96.9%±1.1%, 96.3%±1.4%, 96.0%±1.7%, 95.6%±1.8% and 95.2%±2.7%, respectively. There were statistically significant differences in the average SpO₂ values of newborns at different altitudes (right hand: F=1 248.35, P<0.001; either foot: F=1 280.45, P<0.001). The SpO₂ of newborns tended to be lower with the increase of altitudes (P-trend<0.001). Conclusion: SpO₂ values in newborns were negatively associated with the altitudes, which indicated that the cut-off value of screening for NCHD at sea level might not be applicable to newborns at higher altitudes. Thus, it is worthwhile to conducted studies on the normal values of SpO₂ and the cut-off value of screening for NCHD in newborns at high altitudes.