Objective: To describe the changes in oxygen saturation (SpO2) in healthy infants during the first 10 minutes of life.
Study design: In this observational study, infants > or = 35 weeks gestation at birth who did not require supplemental oxygen had continuous recordings taken of the preductal SpO2 over the first 10 minutes of life.
Results: A total of 115 infants were analyzed. On average, infants delivered by cesarean delivery had a 3% lower SpO2 than infants delivered by vaginal delivery (95% confidence interval [CI] = -5.8 to -0.7; P = .01). Infants born by cesarean delivery also took longer (risk ratio, 1.79) to reach a stable SpO2 > or = 85% (95% CI = 1.02 to 3.14; P = .04). At 5 minutes of age, median SpO2 values (interquartile range) were 87% (80% to 95%) for infants delivered vaginally and 81% (75% to 83%) for those delivered through cesarean section. The median SpO2 did not reach 90% until 8 minutes of age in either group.
Conclusions: The process of transitioning to a normal postnatal oxygen saturation requires more than 5 minutes in healthy newborns breathing room air.