Immature sleep pattern in newborn rats when dams encountered sleep restriction during pregnancy

There is a growing realization that proper sleep during pregnancy is essential for the health of the mother and the offspring. However, there are no reports on the effects of maternal sleep restriction on the sleep-wake profiles of newborns. So, this study was conducted to evaluate the effects of sleep restriction during the third term of pregnancy on the sleep-wake profiles of neonates born to them. The female pregnant Wistar rats were sleep restricted for 5 h/day on gestational days 15-20 by gentle handling. Sleep-wake profiles of the pups born to them and to the control rats were recorded on postnatal days 1-21. Pups of sleep restricted dams had higher active sleep (AS) and lower quiet sleep (QS) as well as wakefulness. Higher ratio of AS to QS, longer duration of sleep cycles, lesser bout frequency and reduced EEG delta power were also observed in these pups, all of which indicated brain immaturity. All these signs of delayed maturation, usually found in premature babies, were observed in the pups of sleep restricted mothers, who had longer gestation period. This report not only shows the importance of sleep during pregnancy, but it also suggests that neonatal sleep monitoring can be used as a tool for early assessment of retarded brain development.