The reports were based on findings presented at the European Society of Human Reproduction meeting in Rome last week.

Dr Fahimeh Ramezani Tehrani, from Shahid Beheshti University of Medical Sciences in Tehran, Iran, and colleagues analysed blood samples from 266 women aged 40-49. Using levels of anti-Mullerian hormone (AMH), they were able to predict when women would enter the menopause.

Dr Fahimeh Tehrani and her team's predictions were, on average, accurate to within four months and the maximum margin of error was four years.

The researchers believe their findings could be helpful in identifying women likely to go through the menopause early.

Who might use these forecasts?
'The results from our study could enable us to make a more realistic assessment of women's reproductive status many years before they reach menopause,' Dr Ramezani Tehrani said.

'For example, if a 20-year-old woman has a concentration of serum AMH of 2.8ng/ml, we estimate that she will become menopausal between 35 and 38 years old.'

She added: 'We believe that our estimates of ages at menopause based on AMH levels are of sufficient validity to guide medical practitioners in their day-to-day practice, so that they can help women with their family planning.'

Is this a major step forward?
Tony Rutherford, chairman of the British Fertility Society chairman, said that researchers have previously struggled to find an accurate predictor of when a woman would go through the menopause, although anti-Mullerian hormone has been seen as a good candidate for resolving the issue.

'This interesting study describes a new model that directly links anti-Mullerian hormone levels to age at menopause, with the validation of having studied the participants over a number of years,' he said.

But, he added: 'It is important to emphasise that this is only a preliminary study and further long-term randomised clinical trials are needed to confirm the accuracy of the predictive values, particularly in younger women.

'Fertility declines dramatically in the years leading up to menopause and it is important that women do not see tests of this nature as a reason to delay starting a family.'

• European Society of Human Reproduction meeting 2010

Informing Patients
Iranian researchers have developed a test to predict when women will enter the menopause. The test uses anti-Mullerian hormone and is accurate to within four months. The test's usefulness for family planning is limited because fertility can decline before the menopause.