Danish researchers at Copenhagen University Hospital have found that a woman’s age at menopause could significantly affect the fertility of her daughter.
The study, published in the journal Human Reproduction, was conducted among 863 women aged between 20 and 40 years. All participants were initially surveyed through an internet-based questionnaire to obtain data on reproductive history and family medical history.
The final study group consisted of 527 participants whose mother’s age at menopause was known.
Researchers then used two methods to determine the number of eggs, or the “ovarian reserve”, that each woman had. The first method looks at the levels of anti-Mullerian hormone (AMH) present in the bloodstream. AMH is the hormone produced by cells in the antral follicles. Antral follicles are dormant immature eggs that will eventually develop and mature when they wake from their dormant state. The second method is an antral follicle count (AFC), which is done by ultrasound. As a woman runs out of eggs, her AFC will decline, along with her levels of AMH. Both are accepted methods of determining a woman’s ovarian reserves.
The results showed that both the AMH and AFC levels in women whose mothers reached menopause before the age of 45 declined much faster compared to women whose mothers reached menopause after age 55.
The annual decline of AMH and AFC levels in women with mothers who had early menopause was found to be 8.6% and 5.8% respectively. In normal age menopause the decline was 6.8% and 4.7%, and in late menopause it was 4.2% and 3.2%.
Study leader Dr Janne Bentzen said, "Our findings support the idea that the ovarian reserve is influenced by hereditary factors. However, long-term follow-up studies are required."
However, experts say that women should not be concerned as there’s no proof that having fewer eggs means you will not be able to have the number of children you want. A spokesman for the British Fertility Society, Dr Valentine Akande said "There is a huge amount of variation among women. Some will have more eggs and some will have less… The advice remains the same - the younger you start trying for a baby the more likely you are to be successful."