Why fertility is linked to mum's age at menopause
A woman's potential fertility can be predicted from the age her mother went through the menopause.
In a recent study, ovarian reserve -- the number of eggs a woman has left in her ovaries -- was found to decline faster in women whose mothers had an early menopause.
The findings suggest that a woman's fertility is, to some extent, inherited.
Earlier statistical studies had already indicated the trend, but the new research confirmed it by looking at two physical markers of ovarian reserve.
Scientists measured anti-Mullerian hormone (AMH) levels and antral follicle count (AFC) in daughters and compared both with mothers' age at menopause. Both markers reduced at a faster rate in daughters of mothers who had the menopause early.
Study leader Dr Janne Bentzen, from Copenhagen University Hospital in Denmark, said: "This is the first study to suggest that the age-related decline of AMH and AFC may differ between those whose mothers entered menopause before the age of 45 years and those whose mothers entered menopause after the age of 55 years.
"Our findings support the idea that the ovarian reserve is influenced by hereditary factors. However, long-term follow-up studies are required.
"Conclusive evidence can only be obtained when we have longitudinal studies that follow women who have AMH measurements over time until menopause."
A total of 527 women, aged 20 to 40, working in health care at Copenhagen University Hospital took part in the research.
They were divided into those whose mothers had an early menopause up to the age of 45, those whose mothers had a normal menopause between the ages of 46 and 54, and those whose mothers had a late menopause at 55 and older.
Average AMH levels declined by 8.6pc, 6.8pc, and 4.2pc per year in women with mothers who had early, normal or late menopauses respectively.
A similar pattern was seen for AFC, with annual declines of 5.8pc, 4.7pc and 3.2pc per year in the same groups.
The results are reported in the latest online edition of the journal Human Reproduction.