Figure 1.

Changes in mean PSQI score and subscores by postpartum week.

—PSQI total score*

------- Sleep efficiency, subscore 4*

_ _ _ Sleep duration, subscore 3*

PSQI - Pittsburgh Sleep Quality Index.

Reduced scores indicate better global sleep quality, better sleep efficiency, and longer sleep duration.

Error bars: 95% confidence interval.

*Significant change (P < 0.01, linear regression). The PSQI subscores 1: Subjective sleep quality, 2: Sleep onset latency, 5: Sleep disturbances, 6: Sleep medication and 7: Daytime dysfunction did not show significant changes by postpartum week, and are not shown.