Sequential recordings (total number 365, mean duration 22 hours) of ECG and abdominal wall movement were obtained from 110 full-term infants up to 6 months of age. The longest pause in breathing movement per recording (maximum 21.6 seconds) decreased in duration over the first 2 weeks of life (P < .005). Pauses >18.0 seconds were not detected after seven days. The spread of values for pauses ≥3.6 seconds duration was widest during the first 2 weeks, and their number decreased with age (P < .001). Periodic breathing, detected in 69% to 80% of infants in all age groups, showed decreasing trends with age in total duration and maximum length of episode (P < .005 for both). The spread of values was widest during the first 2 weeks (range for total duration 0 to 4.7 hours) and decreased with age. The mean respiratory rate during regular breathing decreased after 4 weeks (P < .001). The spread of values was widest during the first 2 weeks and decreased with age. Birth weight was positively correlated with mean respiratory rate during the first three days of life (r = +.64, P < .001). The mean heart rate during regular breathing increased during the first 15 days (P < .001) and then decreased after 4 weeks (P < .001). Higher mean heart rates were found in male infants (P < .01).
- Received November 3, 1983.
- Accepted March 13, 1984.
- Copyright © 1984 by the American Academy of Pediatrics