Analyses of mothers' sleep logs in postpartum periods.

In order to investigate mothers' sleep-wake patterns from five to 12 weeks in the postpartum period, we analyzed continuous sleep logs. Data for 341 days from seven mothers were analyzed for each postpartum week. There were significant differences in total sleep time and wake time at night. Wake time at night gradually decreased from the fifth to the twelfth week. These results from continuous sleep logs support the results of our previous polysomnographic findings based on intermittent measurements. A transition from interrupted sleep to noninterrupted sleep was observed from the ninth to twelfth week of postpartum. The mothers' sleep-wake patterns are discussed focusing on their relationships to the infants' sleep-wake patterns and feeding rhythm.