Women who work nights are 9% more likely to have an early menopause

Women who work night shifts are nine per cent more likely to have an early menopause – even if it is only occasionally

  • Disrupts the sleep-hormone melatonin, which may affect the ovaries
  • Stress and tiredness might interfere with oestrogen, triggering early menopause
  • Early menopause raises the risk of heart disease and osteoporosis 
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Women who work night shifts may risk going through the menopause at a younger age.

Even occasional night shift workers are nine per cent more likely to have an early menopause, a study has found.

This matters because women who go through the menopause younger are at greater risk of cardiovascular disease, osteoporosis and may even suffer memory problems.

Women who work night shifts may go through the menopause at a younger age (stock)

Researchers tracked more than 80,000 nurses who worked night shifts over 22 years. 

The risk of early menopause was found in those who worked almost two years of night shifts.

Women who disrupt their body clocks by staying up at night have lower levels of the sleep-hormone melatonin, which some experts believe is important for the ovaries.

But it may also be the stress and tiredness of night-working which disrupt oestrogen levels and plunge women into menopause at an early age.

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Dr David Stock, who led the study from the University of Dalhousie in Canada, said: ‘This is the first study into a link between rotating night shifts and age at menopause, and we found a moderate but significant link.

‘For women who went through the menopause before the age of 45, shift work seemed to be particularly important. 

‘This could be due to disruption of their circadian rhythms, stress or fatigue, although more research is needed.’ 

Women who work night shifts have a greater risk of breast and endometrial cancer, previous studies have found.


Menopause is defined as the changes a woman goes through just before and after she stops her periods and is no longer able to get pregnant naturally. 

Some women go through this time with few, if any, symptoms, around 60 percent experience symptoms resulting in behavioral changes and one in four will suffer severely. 

Common symptoms include hot flushes, night sweats, vaginal dryness leading to discomfort during sex, disrupted sleep, decreased sex drive, problems with memory and concentration and mood swings.

Menopause happens when your ovaries stop producing as much of the hormone oestrogen and no longer release an egg each month.

In the UK, the average age for a woman to reach the menopause is 51, according to the NHS.

Working at night, even every so often, is believed to affect sex hormone levels, which can lead to cancer or increase the chances that a woman stops ovulating.

The study looked at nurses who had worked at least three nights in a month, in addition to day and evening shifts. 

It found women who had done this for 20 months or more in the preceding two years had a nine per cent greater risk of early menopause.

For those who started the menopause below the age of 45, this many night shifts increased the risk of early menopause by 25 per cent.

If they had done rotating night shifts for more than 20 years, the risk rose to 73 per cent. However the researchers caution this was seen in only a small group of women.

The study, published in the journal Human Reproduction, concludes: ‘Women already prone to earlier menopause may further truncate their reproductive lifetime by working schedules comprising day as well as night shifts.’ 

Night shifts, previously suggested to increase women’s risk of miscarriage and premature birth, are concerning because they expose people to artificial light when they are supposed to be asleep.

This is what reduces levels of the sleep-hormone melatonin, which some experts say is vital for keeping ovaries working and producing eggs so women remain able to have children.

But an early menopause could also come from the stress of working late at night, as stress hormones are believed to disrupt sex hormones like oestrogen.

Previous evidence suggests that working ‘high-strain’ jobs and those with ‘difficult schedules’ is linked to earlier menopause. 

The authors conclude: ‘Given evidence that nurses are commonly called upon to work long shifts, it is plausible that a substantial proportion of participants.. may have met these criteria.’


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