Limitations in home monitoring technology have precluded longitudinal studies of hemoglobin oxygen saturation during unperturbed sleep. The memory monitor used in the Collaborative Home Infant Monitoring Evaluation addresses these limitations. We studied 64 healthy term infants at 2 to 25 weeks of age. We analyzed hemoglobin oxygen saturation by pulse oximetry (SpO2), respiratory inductance plethysmography, heart rate, and sleep position during 35,127 epochs automatically recorded during the first 3 minutes of each hour. For each epoch baseline SpO2 was determined during ≥10 s of quiet breathing. Acute decreases of at least 10 saturation points and <90% for ≥5 s were identified, and the lowest SpO2 was noted. The median baseline SpO2 was 97.9% and did not change with age or sleep position. The baseline SpO2 was <90% in at least 1 epoch in 59% of infants and in 0.51% of all epochs. Acute decreases in SpO2 occurred in 59% of infants; among these, the median number of episodes was 4. The median lowest SpO2 during an acute decrease was 85% (10th, 90th percentiles 78%, 87%); 79% of acute decreases were associated with periodic breathing, and ≥16% were associated with isolated apnea. With the use of multivariate analyses, the odds of having an acute decrease increased as the number of epochs with periodic breathing increased, and they lessened significantly with age. We conclude that healthy infants generally have baseline SpO2 levels >95%. The transient acute decreases are correlated with younger age, periodic breathing, and apnea and appear to be part of normal breathing and oxygenation behavior.
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health