A simple blood test can give an accurate pointer of when a woman will hit the menopause, according to research to be presented at a fertility conference in Rome on Monday.
If confirmed by other scientists, the test devised by Iranian doctors would be a boon for women seeking to plan when to start a family, the European Society of Human Reproduction and Embryology (ESHRE) said in a press release on Sunday.
The test is based on levels of so-called anti-Mullerian hormone (AMH), which controls the development of egg-making cells in the ovary.
A team led by Fahimeh Ramezani Tehrani, a professor at the Shahid Beheshti University of Medical Sciences in Tehran, took blood samples at three yearly intervals among 266 women aged 20 to 49 who were enrolled in a different project launched in 1998.
The women also had physical examinations every three years.
The investigators developed a statistical model that looked at changes in AMH levels and predicted when menopause would take effect.
Sixty-three of the women reached menopause during the study's duration, and the predictions were extremely accurate, Ramezani Tehrani said.
"The average difference between the predicted age at menopause using our model and the women's actual age was only a third of a year," she said.
The maximum margin of error was three to four years.
If a 20-year-old woman has 4.1 nanograms per millitre of AMH, or less, in her blood sample, she is a higher risk of early menopause, meaning before the age of 45.
In contrast, AMH levels of at least 4.5 nanograms per millilitre of AMH at the age of 20, followed by 3.8 nanogramms at the age of 25 and 2.9 nanograms at the age of 30 suggest that menpause will occur beyond the age of 50.
"Our findings indicate that AMH is capable of specifying a woman's reproductive status more realistically than chronological age per se," said Ramezani Tehrani.
Further work is needed among a larger group of women in their twenties to confirm the accuracy of the technique, she added.
The ESHRE conference, gathering thousands of European fertility specialists, continues in Rome until Wednesday.