Infants' earliest sleep/wake organization differs as a function of delivery mode.

The sleep/wake states of newborn infants were investigated as as a function of vaginal and C-section delivery. The subjects were 51 normal full-term infants: 26 vaginally delivered, 12 delivered by emergency C-section, and 13 delivered by elective C-section. Their sleep states and wakefulness were continuously recorded from the time of birth throughout their stay in the hospital, that is, the first 2 postnatal days for the vaginally delivered infants and 5 days for the C-section infants. Sleep was recorded using the automated Motility Monitoring System, which permits 24-hr recordings without instrumentation of the subject. During the 1st postnatal day, both C-section groups showed state patterns that differed significantly from those of the vaginally delivered infants. Analyses for single states indicated that both C-section groups had significantly less active sleep, and the elective group had more wake and more sleep--wake transition than the vaginal group. The two C-section groups did not differ significantly on any measure. Only the vaginally delivered infants showed significant day/night differences during the first 2 days, with more wakefulness, shorter mean sleep periods and shorter longest-sleep periods during the daytime on both days. The results of this study indicate that the earliest postnatal sleep patterns differ and the diurnal sleep rhythm is disrupted as a result of surgical delivery.