Apnea recordings of healthy infants at 40, 44, and 52 weeks postconception.

A total of 129 recordings of the respiratory activity of 46 normal full-term infants were obtained continuously for 24 hours in the hospital nursery at 3 days of life and in the home environment at 4 weeks and 12 weeks after birth. The pediatric pneumogram (PPG) technique, an impedance method, was used. Pneumogram data over longer than 16 hours was obtained on 77% of infants monitored. No infants experienced apnea longer than 15 seconds in duration at 40 and 44 weeks postconception, or greater than 11 seconds at 52 weeks postconception. Twenty-four hour plots of hourly apnea frequency revealed a marked variability, with evidence of clustering of apneic episodes during periods of reported sleep. Longest apnea time and hourly frequency of apneic episodes were highly correlated.