Fundamental Change in Understanding of Postpartum Sleep

Medscape

4 days ago

SEATTLE — The lack of uninterrupted sleep, rather than the lack of total sleep, appears to be the biggest challenge for new first-time moms and is a defining feature of postpartum sleep disruption, new data suggested. Investigators said the findings highlighted a previously understudied area of research and could be important for maternal health.
The study showed that sleep duration was significantly reduced during the first postpartum week but gradually returned to near prepregnancy levels thereafter. However, the longest stretch of uninterrupted sleep remained considerably below preconception levels throughout the first 13 postpartum weeks.
'The significant loss of uninterrupted sleep in the postpartum period was the most dramatic finding. While mothers generally returned to their prepregnancy total nightly sleep duration after the first postpartum week, the structure of their sleep remained profoundly altered,' lead author Teresa Lillis, PhD, adjunct professor of psychiatry and behavioral sciences at Rush University Medical Center in Chicago, said in a news release.
Teresa Lillis, PhD
'These results fundamentally change our understanding of postpartum sleep by introducing a metric commonly used in the infant sleep literature that previous maternal sleep researchers have overlooked — the longest uninterrupted stretch of sleep,' Lillis told Medscape Medical News.
The results showed that 'sleep discontinuity — not sleep loss — is the defining feature of postpartum sleep disruption — one that may have profound implications for maternal health,' Lillis added.
The findings were presented on June 9 at the SLEEP 2025.
Novel Data on Sleep Disruption
The study included 41 first-time mothers aged between 26 and 43 years. Researchers analyzed sleep/wake data logged in Fitbit trackers from a full year before childbirth to the end of the first postpartum year.
They used the data to calculate sleep duration and longest stretch of sleep for each 24-hour day, comparing the first 13 postpartum weeks with the same days of the prior year (preconception baseline).
The results showed that the average daily sleep duration of new mothers was 4.4 hours during the first week after giving birth compared with a prepregnancy sleep duration of 7.8 hours.
The longest stretch of uninterrupted sleep for new mothers fell from 5.6 hours before pregnancy to 2.2 hours during the first week after delivery.
But while total daily sleep crept back to 6.7 hours in postpartum weeks 2-7, new moms received only 3.2 hours of uninterrupted sleep by that time. In postpartum weeks 8-13, moms logged 7.3 hours of total daily sleep compared to just 4.1 hours of uninterrupted sleep.
'This persistent reduction in uninterrupted sleep explains why mothers continue to feel exhausted even when they appear to be getting 'enough' sleep on paper,' Lillis said.
Mental and Physical Hit
Sleep discontinuity has been shown to have negative effects on cognitive functioning, mood and emotion regulation, and less restorative physical recovery than uninterrupted sleep, Lillis noted.
'But by focusing only on total sleep time in previous research, we've overlooked a critical risk factor and intervention target for postpartum depression and other postpartum health-related issues,' Lillis told Medscape Medical News .
Lillis said the current findings validate the lived experience of new mothers' exhaustion and provide a new target for sleep-related interventions.
'Healthcare providers need to shift their mindset from traditional advice that focuses on adding minutes to total sleep duration (like 'nap when the baby naps') to prioritizing strategies that protect opportunities for uninterrupted sleep,' Lillis said.
The most effective immediate intervention is helping mothers identify a support person (partner, family member, friend, or hired help) who can take over infant care for extended periods, allowing mothers to achieve longer sleep stretches (ideally 4+ hours), Lillis said.
'The key message here is that consolidated sleep, not just total sleep, should be the therapeutic target,' Lillis told Medscape Medical News .
Commenting on this research for Medscape Medical News , Kin Yuen, MD, spokesperson for the American Academy of Sleep Medicine, said, 'What is novel is establishing how long sleep is disrupted postpartum with objective data.'
'This is also the longest tracking data before delivery that I know of, showing at baseline that these mothers had relatively normal sleep. The more extended and abrupt the sleep loss is, the more sleep pressure accumulates and likely dysfunction of cognition and mood result,' said Yuen, sleep medicine specialist with the Sleep Disorders Center, UCSF Health.
'Prior studies have shown that first-time mothers suffer the most acute sleep loss compared to baseline and had more dysfunction subsequently. Overall, it's helpful to know and quantify the amount of sleep loss before and after pregnancy to further understand the impact of sleep loss for new mothers and identity potential interventions,' Yuen said.