Longitudinal assessment of hemoglobin oxygen saturation in preterm and term infants in the first six months of life

J Pediatr. 2011 Sep;159(3):377-383.e1. doi: 10.1016/j.jpeds.2011.02.011. Epub 2011 Apr 9.


Objective: To report longitudinal home recordings of hemoglobin O(2) saturation by pulse oximetry (Spo(2)) during unperturbed sleep in preterm and term infants.

Study design: We recorded continuous pulse oximetry during the first 3 minutes of each hour of monitor use (nonevent epochs) for 103 preterm infants born at <1750 g and ≤ 34 weeks postmenstrual age (PMA), and 99 healthy term infants.

Results: Median baseline Spo(2) was approximately 98% for both the preterm and term groups. Episodes of intermittent hypoxemia occurred in 74% of preterm and 62% of term infants. Among infants with intermittent hypoxemia, the number of seconds/hour of monitoring <90% Spo(2) was initially significantly greater in the preterm than the term group and declined with age at a similar rate in both groups. The 75(th) to 95(th) percentiles for seconds/hour of Spo(2) <90% in preterm infants were highest at 36 weeks PMA and progressively decreased until 44 weeks PMA, after which time they did not differ from term infants.

Conclusions: Clinically inapparent intermittent hypoxemia occurs in epochs unperturbed by and temporally unrelated to apnea or bradycardia events, especially in preterm infants at 36 to 44 weeks PMA.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Female
  • Hemoglobins / metabolism*
  • Humans
  • Hypoxia / epidemiology
  • Infant
  • Infant, Newborn
  • Infant, Premature*
  • Longitudinal Studies
  • Male
  • Monitoring, Physiologic
  • Oximetry
  • Oxygen / metabolism*
  • Term Birth*


  • Hemoglobins
  • Oxygen