Abstract Body: Importance: It is anticipated that many women do not get enough sleep after delivery. However, it is unclear how poor sleep affects postpartum blood pressure.
Objective: To investigate the relationship between postpartum blood pressure and sleep habits, we examined women who developed hypertensive disorders of pregnancy by using automated blood pressure monitors and accelerometers.
Setting: The blood pressure, pulse rate, and sleep were monitored at home. Total sleep time, sleep efficiency, sleep fragmentation coefficient, and wake after sleep onset were measured. Participants completed a behavior chart including breastfeeding frequency. The 24-hour, awake time and sleep time mean blood pressures were calculated for each participant as well as the change in blood pressure between postpartum days 7 and 14.
Participants: We recruited 11 women who delivered singletons and developed hypertensive disorders of pregnancy at the National Center for Child Health and Development from April to September 2021.
Intervention or Exposure: None
Main Outcomes: The relationship between the change in blood pressure and sleep measurements and frequency of breastfeeding were analyzed.
Results: Seven participants were included in the final analysis. The mean total sleep time was 5.3 hours, and the mean breastfeeding frequency was 6.1 times per day. Mean systolic and diastolic blood pressure and pulse rate during sleep periods tended to be lower than those during awake periods (-8.5±4.5 mmHg, -8.8±2.7 mmHg, -8.7±2.7 bpm, respectively). Lower sleep time was significantly correlated with smaller 24h-systolic and diastolic blood pressure drop (correlation coefficient r=-0.823, p=0.023 and r=-0.812, p=0.026, respectively. No association was found between other sleep measurements and the change in 24h-blood pressure. The blood pressure and pulse rate values in six of the seven participants during the early sleep phase (≤30 min) were similar to those in later sleep phases (>30 min), showing that beneficial effects of sleep on blood pressure were apparent throughout the sleep phases.
Conclusions and Relevance: Our results suggest that longer total sleep time, even if sleep is fragmented, is associated with a greater decrease in postpartum blood pressure among women who developed hypertensive disorders of pregnancy.