PurposeThis study was to clarify the characteristics and changes of the sleep-wake rhythm in mothers from late pregnancy to four months postpartum.
MethodsParticipants were 57 women in late pregnancy to four months postpartum. The subjects were 57 mothers after 35 weeks of pregnancy who gave informed consent to participate. Of these, forty-seven mothers 1 month postpartum and thirty-four at 4 months postpartum, were surveyed longitudinally at.
Participant recorded 24 hours sleep-and-wakefulness using a day-by-day plot method on Sleep Log at intervals of 30 minutes for one week.
We calculated sleep parameters: total sleep time (TST), nocturnal sleep time (NST), diurnal sleep time (DST), longest sustained sleep period (LSP), LSP onset and offset times, numbers of total sleep hours and diurnal sleep hours, time of waking after sleep onset (WASO), number of WASO and sleep-wake cycle.
ResultsTST were 7.79 hours in late pregnancy, 6.73 hours 1 month postpartum and 6.91 hours in 4 month after delivery (F=18.21, p<0.001). NST were 6.75 hours, 5.85 hours and 6.36 hours (F=12.27, p<0.001) respectively. LSP were 6.39 hours, 3.46 hours and 4.13 hours (F=87.61, p<0.001). TST, NST and LSP in postpartum were shorter than those late pregnancy. WASO were 0.42 hours, 1.70 hours and 1.14 hours (F=45.42, p<0.001). Number of WASO were 0.3 times, 1.7 times and 1.5 times (F=78.60, p<0.001). WASO in postpartum was longer than those late pregnancy, and number of WASO in postpartum was larger than those late pregnancy.
It was found that LSP showed significant negative correlation with LSP onset in late pregnancy (r=-0.481, p<0.001), and 4 months postpartum (r=-0.396, p<0.05).
In addition, LSP were predominantly between 0:22 and 6:50, while cycle of sleep-and-wakefulness rhythm was approximately 24 hours, which showed a range of 24.04 hours to 24.08 in the mothers in this study.
ConclusionThe sleep-wakefulness rhythm in mothers is disturbed from late pregnancy to postpartum, although TSP, NSP, LSP decrease and WASO increases. The mothers who go to bed early are able to sleep longer during nighttime hours and sleep-and-wakefulness was approximately 24 hours cycle in all mothers.
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