Female fertility declines with age because genetic damage accumulates in a woman's eggs, shows study. Women who delay motherhood are likely to increase the risk of damaging the fertility of their daughters.
This genetic damage that builds up in older eggs gets passed on to daughters, reducing the quality of their own egg, reports the Guardian. Importantly, the age of the women's fathers had no significant effect.
"A mother's reproductive age is important not only for herself, but it will determine to a certain extent the chances of her daughter or daughters being infertile," Peter Nagy, from Reproductive Biology Associates in Atlanta, was quoted as saying.
The age of menopause varies, but is typically around 50. The nearer a woman is to menopause when she gives birth, the higher the chance her daughter will have impaired fertility
The researchers, presenting the results at the American Society of Reproductive Medicine in New Orleans, said it was too early to predict the impact of the effect.
However, they fear the trend for couples to put off starting families until their mid-30s and beyond will see increasing numbers of young women needing fertility treatment simply because they were born to older mothers.
In the study, women who had on average slightly younger parents, with fathers aged 28.2 and mothers aged 25.7 became pregnant, while women, whose parents were on average 31.9 and 28.2, failed to get pregnant
Further, women who failed to conceive were born to mothers who were on average five years closer to the menopause. They were born when their mothers were an average of 19.6 years away from the menopause, compared with 24.7 years for women who did get pregnant.