Background and Aims As sleep-wake cycling (SWCing) of healthy infants within hours of birth has not been quantified with conventional EEG monitoring, in this study we examine the SWC composition of healthy term infants in the immediate postnatal period using EEG, and investigate factors that might influence neonatal sleep.
Methods Multichannel video-EEG was recorded for up to 2.5 hours in healthy term infants soon after birth. The total amount and percentages of sleep states (SSs) were calculated for each infant. Parametric/non-parametric statistical testing was used to test the influence of maternal and infant-related factors on SSs.
Results Ninety-one healthy term infants aged 1 to 36 hrs were studied (< 6 hrs – 21, 6–12 hrs – 47, 13–24 hrs – 11, and 25–36 hrs – 12). A well-developed SWC was evident as early as within the first 6 hrs after birth. The mean (SD) percentage of active sleep (AS) was 52.1% (12.9), quiet sleep (QS) - 38.6% (12.5). AS was longer and QS shorter in infants delivered by elective caesarean section (CS) compared to infants delivered by vaginal delivery (AS: p=0.01; QS: p=0.02) or emergency CS (AS: p=0.04, QS: p=0.02). Five infants did not have any SWC present. Disrupted SWCs correlated significantly with the absence of a spontaneous onset of labour (p=0.03).
Conclusion This is the first time that SWC composition has been quantified using EEG monitoring so early in the postnatal period. AS dominates and SWC is clearly present immediately after birth. SWC composition appears to be influenced by labour and mode of delivery.