The most fertile women tend to have mothers who experience late menopause, researchers say today.
The new findings, from Denmark, show a close link between age of menopause and the number of eggs in the ovaries.
Researchers say the findings suggest a strong hereditary influence on a woman’s "ovarian reserve" – the number of eggs she has available at different ages.
The findings, reported in the journal Human Reproduction, come from a study of some 527 women aged between 20 and 40 – and their mothers. Ultrasound was used to measure their ovaries and hormone tests were also conducted.
The researchers found that women in families with a history of early menopause experienced an annual decline in potential eggs of nearly 6% – compared with a 3% decline in those with late menopause, experienced after the age of 55.
The ultrasound measured the number of follicles in the ovaries. A woman is born with about two million of these – but only about 400 mature enough to release an egg.
Researcher Dr Janne Bentzen, of the Copenhagen University Hospital, Rigshospitalet, Denmark, said: "Our findings support the idea that the ovarian reserve is influenced by hereditary factors. However, long-term follow-up studies are required."
She added: "Epidemiological studies have established a link between the age at menopause among mothers and daughters. In line with the suggested 20-year interval between the first decline in fertility and the menopause, we hypothesised that maternal factors may also have an impact on a woman’s fertility potential in terms of ovarian reserve."
Maternal menopause as a predictor of anti-Mullerian hormone level and antral follicle count in daughters during reproductive age. Human Reproduction November 7 2012; doi:10.1093/humrep/des356
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