Women who've been severely sexually abused as a child are starting menopause 11 years earlier than average, a University of Otago study reveals. 

Most women enter menopause, which is the decline in reproductive hormones marking the end of their menstrual cycle, after turning 51 years old. 

This New Zealand study, published in the Journal of the North American Menopause Society, found more than 60 per cent of those who had entered menopause by age 40 had been severely sexually abused as a child. 

Department of Psychological Medicine researcher Dr Geri McLeod, who co-authored the study, said people should care about these findings because women who started menopause that early were less likely to be able to have a baby and more at risk of heart diseases, dementia and other comorbidities. 

"It's frightening to be honest, especially considering fertility and long-term problems for their health. I think it might scare a few people," McLeod said. 

Dr Geri McLeod from the University of Otago's Department of Psychological Medicine. Photo / Supplied 

She said no one really understood exactly why women who were sexually abused as a child were more likely to enter menopause earlier. 

"But the theory was the stress from the abuse changes the hormonal profile even at that young age and then that leads to fast reproductive ageing." 

McLeod said while the findings were consistent with the emerging international literature on the long-term health and developmental impacts of childhood sexual abuse, female health issues had not been well-researched in the past. 

"Knowledge about the long-term impacts of childhood maltreatment on the menopause transition is limited. What little research has been done has shown inconsistent results, possibly due to the research methods used." 

This new research examined data from the Christchurch Health and Development Study (CHDS), which tracked thousands of people born in the city in 1977. 

Participants were now aged 46. When data for this research was collected they were aged 40. 

From the CHDS, 468 females had reported, at age 18 and 21, if they were exposed to sexual abuse or not and were able to answer questions about their menopause status at age 40. 

Of the 468, 104 (22 per cent) were classified as peri or post-menopausal. Of those, more than 60 per cent had been severely abused as a child. 

"Those who'd reported severe sexual abuse, involving attempted or completed sexual penetration, entered the menopause transition at twice the rate of those who hadn't reported such abuse," McLeod said. 

The study also set out to explore if childhood physical abuse led to an early transition to menopause. 

"Previous research had indicated that physical abuse would also hasten menopause. However, in this study, women who reported severe physical punishment in childhood did not have any increased risk of entering the menopause transition by age 40, unlike those unfortunate enough to have been exposed to sexual abuse," McLeod said. 

Sexual harm – Where to get help 

If it's an emergency and you feel that you or someone else is at risk, call 111. 
If you've ever experienced sexual assault or abuse and need to talk to someone, contact Safe to Talk confidentially, any time 24/7: 
• Call 0800 044 334 
• Text 4334 
• Email [email protected] 
• For more info or to web chat visit safetotalk.nz 
Alternatively contact your local police station – click here for a list.