A DNA test to show women how many childbearing years they have left is being developed by scientists.
The test can monitor the speed of a woman’s biological clock to reveal how many eggs she has left and provide an early warning of declining fertility.
The test follows the discovery of a gene called Fragile X, which indicates the rate at which a woman’s egg supply diminishes over time.
Women are born with a limited amount of immature eggs, only a small proportion of which turn into mature eggs. A women’s ‘ovarian reserve’ naturally falls throughout life but about one in 10 women also suffer form early ovarian ageing. This means their fertility declines much earlier than normal, often in their 20s.
The test can reveal whether women are at risk of early ovarian ageing, allowing them to decide whether to start a family sooner, or freeze some eggs to increase the chances of having a child in her 30s.
“We can take an 18 or 20-year-old girl and check her Fragile X and make a pretty good prediction of whether she’s at risk,” said Professor Norbert Gleicher of the Center for Human Reproduction, New York, where the test is being developed.
Professor Gleicher hopes to offer a trial test to women next year, however, other researchers says the study needs to be repeated over several years.