Maternal sleep often changes before birth and remains unsettled after it. Across cohorts, surveys, actigraphy, and consumer wearables, measurements show shorter or more fragmented sleep, rising insomnia in late pregnancy, and gradual—but uneven—postpartum improvement. The figures below retain each study’s own definitions, time periods, and populations.
Contents
- Sleep duration before and during pregnancy
- Sleep quality and insomnia across pregnancy
- Early postpartum sleep duration
- Fragmentation, awakenings, and sleep efficiency
- Sleep trajectories through two years postpartum
- Wearable-measured changes
- Postpartum subgroups and activity
Sleep duration before and during pregnancy
The amount of sleep reported or measured during pregnancy varies by study design. A Norwegian population-based cohort of 1,480 women recorded a mean of 7 hours 16 minutes at week 32 of pregnancy. The same cohort recorded 6 hours 31 minutes at 8 weeks postpartum and 6 hours 52 minutes at 2 years postpartum. These measurements came from the 2008–2010 cohort period. (Trajectories of maternal sleep problems before and after childbirth)
A late-pregnancy postal survey found a clearer difference from the pre-pregnancy baseline. Mean nighttime sleep fell from 8.1 hours before pregnancy to 7.5 hours in the last week of pregnancy, a reported mean reduction of 35.8 minutes per night. In that survey, 9% of women slept under 7 hours before pregnancy, compared with 32% in the last pregnancy week. The share sleeping under 6 hours rose from 2% before pregnancy to 16% in the last week. (A postal survey of maternal sleep in late pregnancy)
| Measure | Before pregnancy | Late pregnancy | Source period |
|---|---|---|---|
| Mean nighttime sleep | 8.1 hours | 7.5 hours | Last pregnancy week; 2012 survey |
| Sleeping under 7 hours | 9% | 32% | Last pregnancy week; 2012 survey |
| Sleeping under 6 hours | 2% | 16% | Last pregnancy week; 2012 survey |
Wearable data provide a different measurement perspective. In a 2025 study of de-identified Fitbit users in the United States and Canada, mean pre-pregnancy total sleep time during the 12 weeks before pregnancy was 425.3 minutes per night, or about 7.1 hours. Total sleep time peaked at 447.6 minutes at gestational week 10, with a standard deviation of 47.6 minutes. (Insights into maternal sleep)
Sleep quality and insomnia across pregnancy
Sleep quality tends to worsen as pregnancy progresses, although percentages are not directly interchangeable because studies used different populations and definitions. In a prospective study using a Pittsburgh Sleep Quality Index score greater than 5, clinically significant poor sleep quality affected 27.91% of women in the first trimester, 34.26% in the second trimester, and 77.67% in the third trimester. Mean PSQI scores were 4.07, 4.66, and 8.16 across those three trimesters. (Sleep quality among pregnant women)
An Iranian pregnancy study reported poor sleep quality for 84.7% of participants in the second trimester and 93.3% in the third trimester. The geography and cohort are specific to that report and should not be treated as a worldwide estimate. (Daytime Napping and Nighttime Sleep During Pregnancy and Preterm Birth in Iran)
The Akershus Birth Cohort study reported insomnia in 60% of women at week 32 of pregnancy. A separate late-pregnancy postal survey found that 82% rated their sleep very good or fairly good before pregnancy, but only 29% gave that rating in the last pregnancy week. The same survey found 4% rated sleep fairly bad or very bad before pregnancy, compared with 38% late in pregnancy. (Trajectories of maternal sleep problems before and after childbirth; A postal survey of maternal sleep in late pregnancy)
Early postpartum sleep duration
The first postpartum months show low nighttime sleep in several studies, but totals depend on whether daytime sleep is included. Continuous actigraphy measured maternal nocturnal sleep at 7.2 hours on average across postpartum weeks 2–16 in a longitudinal study. Sleep efficiency in that study rose during the same period, suggesting that the average sleep window became less disrupted over time. (Normative longitudinal maternal sleep)
Among first-time mothers in a 2017 study, reported nighttime sleep was about 6 hours at 2 months postpartum, with just under 1 hour of daytime sleep. (Sleep in the Postpartum)
A cohort of lactating mothers reported mean sleep duration of 7.27 hours per day at 2–4 months postpartum. The mean was 7.02 hours per day at 5–7 months and 7.45 hours per day at 12–17 months postpartum. These are daily totals from that cohort, rather than nighttime-only values. (Sleep duration of lactating mothers)
A Garmin feasibility study measured about 8 hours of mean sleep per night in the second trimester and found that total night sleep shortened by an additional 1 hour in the postpartum period compared with the second trimester. From gestational weeks 13 through 38, average daily sleep minutes were between 450 and 500; after gestational week 38, mean daily sleep fell to 435 minutes. (Continuous 7-Month Internet of Things–Based Monitoring)
Fragmentation, awakenings, and sleep efficiency
Sleep duration alone does not describe how restorative a night may be. In the continuous actigraphy study, maternal sleep efficiency increased from 79.7% at postpartum week 2 to 90.2% at week 16. Sleep fragmentation fell from 21.7 fragmentation units at week 2 to 12.8 at week 16. (Normative longitudinal maternal sleep)
Parent and infant characteristics also matter in specific cohorts. In a feasibility study comparing parents of preterm and full-term infants, birth-giving mothers had a median of 2.4 nighttime awakenings at 2 months postpartum in the preterm group and 2.7 in the full-term group. Median actigraphic sleep efficiency was 72.6% for mothers of preterm infants and 78.1% for mothers of full-term infants. (Sleep patterns and psychosocial health of parents)
Among mothers of twins at 1 month postpartum, mean 24-hour total sleep time was 419.8 minutes on weekdays and 414.5 minutes on weekends. (Sleep pattern gender differences and fragmentation in postpartum parents of twins)
Sleep trajectories through two years postpartum
The Norwegian longitudinal study followed sleep problems from late pregnancy through 2 years after birth. Insomnia prevalence remained about 60% at week 32 of pregnancy and 8 weeks postpartum, then fell to 41% at 2 years postpartum. Among women with insomnia at week 32, 68.2% still had insomnia at 8 weeks postpartum and 50.0% still had it at 2 years.
Across the three assessments, 39% met the study’s insomnia criterion at week 32 of pregnancy, 8 weeks postpartum, and 2 years postpartum. Another 29% reported insomnia at week 32 and 8 weeks postpartum but not at 2 years. Forty-three percent reported no insomnia at any assessment, while 34% reported insomnia only at 8 weeks postpartum. (Trajectories of maternal sleep problems before and after childbirth)
Insomnia at both week 32 of pregnancy and 8 weeks postpartum was associated with a relative risk of 3.58 for insomnia at 2 years postpartum before adjustment. This is an association from the cohort, not a prediction that applies identically to every mother.
Wearable-measured changes
The large-scale 2025 Fitbit analysis found that total sleep time at gestational week 10 was 447.6 minutes, compared with a pre-pregnancy mean of 425.3 minutes. Other sleep stages changed in the opposite direction over pregnancy: Fitbit-measured deep sleep decreased by a maximum of 19.2 minutes by the end of pregnancy, with a standard deviation of 13.8 minutes. Rapid-eye-movement sleep decreased by a maximum of 9.0 minutes by pregnancy end, with a standard deviation of 19.2 minutes. (Insights into maternal sleep)
Median Fitbit sleep efficiency declined from 88.3% before pregnancy to 86.8% during pregnancy. Time in bed remained below the pre-pregnancy level after birth: the average difference was 14.7 minutes below baseline at 1 year postpartum and 15.2 minutes below baseline at 1.5 years postpartum. These results describe the device-user sample in the United States and Canada and are not a global forecast.
Postpartum subgroups and activity
In a longitudinal new-parent study, 59% reported less than 7 hours of sleep per night at 2 months postpartum. Forty percent met the 7–9-hour sleep guideline at that point, and only 1% reported more than 9 hours. Guideline attainment rose to 55.2% at 4 months, 55.3% at 6 months, and 53.6% at 8 months postpartum. Fathers slept 0.34 hours more per night than mothers at 4 months and 0.45 hours more at 6 months in that study. (New parents’ sleep, movement, health, and well-being)
Device-based measures from 136 mothers at 6 months postpartum found small activity-related differences in sleep efficiency and interruption. Each additional 10 minutes of daily light physical activity was associated with 0.12 percentage points higher sleep efficiency, while each additional 10 minutes of sedentary time was associated with 0.10 percentage points lower sleep efficiency. Each additional 10 minutes of daily moderate-to-vigorous activity was associated with a 0.65-minute shorter average sleep interruption. Each additional 10 minutes of sedentary time was associated with a 0.36-minute longer average interruption. (Repeated device-based measures of daily movement)
These figures are descriptive statistics from primary cohort, actigraphy, wearable, and prospective observational reports. Definitions—including PSQI greater than 5, DSM-IV insomnia, sleep efficiency, and guideline attainment—remain study-specific, and the populations and geographies are not interchangeable. They are not medical advice.