Clinical observation on 57 normal term neonates was carried out in regard to respiratory frequency, pattern, and occurrence of expiratory grunting from birth through the first hours of life. In addition to the above observation, 29 infants had simultaneous graphic recordings of their respiratory cycles as sensed by a nasal thermistor and sounds over the tracheal region by a contact microphone. Fourteen infants had their breath and grunting sounds, when present, tape recorded from the moment of birth.
Expiratory grunting was observed in 13 of 33 infants whose umbilical cords were clamped late (3 to 5 minutes after birth); while no one demonstrated this sign among the 24 early clamped infants (cords clamped within 5 to 10 seconds of birth). Grunting, when present, started within the first half hour of life with peak frequency at 30 to 60 minutes and, in most, disappeared gradually by the end of the second to the fourth hour. It is suggested that in the presence of an overdistended circulatory system in the late clamped infants, expiratory grunting serves as a compensatory mechanism in some to better achieve respiratory adaptation at birth when conditions are less than optimal.
- Received January 25, 1971.
- Accepted April 27, 1971.
- Copyright © 1971 by the American Academy of Pediatrics