Smartwatch data helps researchers study menopause transition

Smartwatch data may help track menopause sleep changes after researchers analysed more than 94,000 nights of Apple Watch sleep records.

The study analysed more than 94,000 nights of sleep data from 338 participants in the Apple Women’s Health Study.

It found that many participants spent more time awake during the night in the 12 months before and after their final logged menstrual period.

For the past several years, Apple has used the Apple Watch to support large-scale health studies through the Apple Research app.

These include the Apple Women’s Health Study, the Apple Heart and Movement Study, and the Apple Hearing Study, which launched in 2019 with research partners including Harvard, Brigham and Women’s Hospital, the American Heart Association and the University of Michigan.

In February 2025, Apple said those studies had grown to more than 350,000 participants across the US.

Recently, researchers at Harvard T.H. Chan School of Public Health published results on how sleep patterns change during perimenopause.

The study looked at wake after sleep onset, or WASO, which measures how much time a person spends awake after first falling asleep.

In the 18 months leading up to menopause, 60 per cent of women with sleep tracking data showed increased WASO compared with the previous six months.

The average increase was 7 per cent.

Researchers also found that, in the 12 months before and after the last logged menstrual period, participants spent about 0.8 per cent more of their sleep time awake after menopause than before.

However, the findings varied widely between participants.

Some women had much larger increases in time awake after menopause, while others had no meaningful sleep change at all.

The researchers said this reflects the fact that each person experiences perimenopause and menopause differently.

Participants who tracked sleep also logged menopause symptoms.

Hot flushes were reported by 82.3 per cent of participants, irritability by 68.1 per cent, mental exhaustion by 65.7 per cent and sexual symptoms by 65.6 per cent.

Among participants with more severe menopause symptoms, the symptoms most closely linked with worse sleep were bladder symptoms, joint symptoms, heart discomfort and depressive symptoms.

The researchers also shared recommendations that may help women sleep better during perimenopause.

These include maintaining a cool sleeping environment, keeping a consistent sleep schedule, getting regular movement, avoiding common bladder irritants and limiting fluids in the hours before bedtime, and prioritising relaxation or mindfulness techniques as part of a bedtime routine.