Study Quantifies Sleep Loss and Sleep Diorders Among Young Mothers

A new study presented at the SLEEP 2025 Annual Meeting quantifies the sleep loss experienced by first-time mothers in the weeks following childbirth and identifies for the first time the unique type of sleep disturbance that persists during the first months of motherhood. The results show that the average daily sleep duration of young mothers in the first week after giving birth was 4.4 hours, compared to 7.8 hours before pregnancy. Their longest uninterrupted sleep period also decreased from 5.6 hours before pregnancy to 2.2 hours in the first week after giving birth. Almost a third of participants (31.7%) did not sleep for more than 24 hours in the first week with a newborn baby.

Sleep Loss as a Major Challenge

The daily sleep duration of young mothers increased to 6.7 hours in weeks 2 to 7 after birth and to 7.3 hours in weeks 8 to 13. However, their longest uninterrupted sleep phase remained significantly below the pre-pregnancy level, at 3.2 hours in weeks 2 to 7 and 4.1 hours in weeks 8 to 13. This new finding shows that sleep interruptions remain a problem for young mothers even when their total nighttime sleep duration gradually returns to pre-pregnancy levels.

“The significant loss of uninterrupted sleep in the postpartum period was the most dramatic finding,” said lead author Teresa Lillis, who has a PhD in clinical psychology and is an associate professor in the Department of Psychiatry and Behavioral Sciences at Rush University Medical Center in Chicago. While mothers generally returned to their pre-pregnancy total nighttime sleep duration after the first week postpartum, their sleep structure remained profoundly altered. These findings fundamentally change our understanding of postpartum sleep: it is not sleep deprivation, but the lack of uninterrupted sleep that is the biggest challenge for new mothers.

The study involved 41 first-time mothers between the ages of 26 and 43. They provided their portable sleep data from their personal Fitbit devices for a full year before giving birth until the end of their babies’ first year. Lillis noted that these findings explain why young mothers still feel exhausted even when they get the recommended 7 or more hours of sleep per night. The study results also identify sleep interruptions as a potential risk factor and target for interventions for postpartum depression and other postpartum health issues. “Our findings confirm new mothers’ experiences of exhaustion and provide a new starting point for sleep-related interventions,” she said. “Rather than simply encouraging mothers to ‘sleep when the baby sleeps,’ our findings show that mothers benefit most from strategies that allow them to get uninterrupted sleep.”