A new test can predict the age at which menopause will occur, thus making it easier for couples to plan children.
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It goes against the grain of natural selection, yet in humans it is by and large fixed and universal. Around the age of 50, normal healthy women lose their ability to bear children. After a decade of gentle winding down, the reproductive system comes to a halt. Enhanced life expectancy — thanks to decades of development in healthcare — however, hasn’t been able to budge menopausal age even a wee bit. Today, a growing number of women spend almost half their life in the post-reproductive phase.
Scientists continue to be baffled by the phenomenon of menopause. While it hits all women, some unfortunate ones encounter it much early in life. A study by the Bangalore-based Institute for Social and Economic Change about four years ago showed that nearly 4 per cent of Indian women lose their ability to bear children before the age of 35, one of the lowest thresholds of menopause recorded anywhere in the world. The natural age for the onset of menopause is between 45 and 55.
In today’s world of career women and late marriages, getting to know the expected age of menopause would be a great support. It would help couples better plan their children.
A simple blood test may soon make this possible. A team of Iranian scientists — led by Fahimeh Ramezani Tehrani, who heads the Reproductive Endocrinology Department, Endocrine Research Centre, Tehran — say they have developed a test that can accurately predict the onset of menopause with an average error of four months. Ramezani Tehrani is scheduled to present the findings at the 26th annual meeting of the European Society of Human Reproduction and Embryology in Rome today. This is the first effort that can predict the age of menopause from a population-based study, say the scientists.
The researchers found that it is possible to calculate the onset of menopause by measuring the concentrations of a hormone called anti-Mullerian Hormone (AMH), which is produced by cells in women’s ovaries. AMH controls the development of follicles in the ovaries, which produces eggs (oocytes).
The researchers used blood samples from 266 women, aged between 20 and 49. The women were part of a study that has been going on in Tehran since 1988 to evaluate cardiovascular risk factors. The scientists took the samples at three-yearly intervals and also collected information on each volunteer’s socioeconomic background and reproductive history. The women also were subjected to physical examination every three years.
“We developed a statistical model for estimating the menopausal age from a single measurement of AMH concentration in serum from blood samples,” said Ramezani Tehrani, who is also an associate professor at the Shahid Beheshti University of Medical Sciences, Tehran.
AMH, along with the hormone Inhibin B, is secreted by ovaries and is hence a direct reflection of the quality and quantity of the oocytes, said Lakshmi Rao, a scientist at the Hyderabad-based Centre for Cellular and Molecular Biology. Rao, who studies the genetic causes of premature menopause, said this is an important observation for the prediction of menopause.
According to Ramezani Tehrani, there is a good level of agreement between the menopausal ages estimated by their model and the actual ages at which menopause occurred. As many as 63 volunteers reached menopause during the study, helping the scientists validate their model.
“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,” said Ramezani Tehrani.
As per their calculation, a 20-year-old woman who has 2.8 ng/ml (nanograms per millilitre) of AMH in her blood will reach menopause between 35 and 38 years. The scientists used this statistical model to identify AMH levels at different ages that would predict if a woman is likely to have an early menopause (that is, before the age of 45). They found, for instance, that an AMH level of 4.1 ng/ml or less in a 20-year-old woman, 3.3 ng/ml in a 25-year-old, and 2.4 ng/ml in a 30-year-old indicated an early menopause.
Similarly, an AMH level of at least 4.5 ng/ml at the age of 20, 3.8 ng/ml at 25, and 2.9 ng/ml at 30 predicted a menopausal age of over 50 years. The researchers found that the average age at menopause for the women in their study was approximately 52.
The Iranian scientists claimed that their estimates are sufficiently robust and can be used by medical practitioners in their day-to-day practice. They were confident that the findings would be further validated in larger studies.
The findings thus indicate that AMH is capable of specifying a woman’s reproductive status more accurately than chronological age per se. “But considering this is a small study that has looked at women over a period of time, larger studies starting with women in their twenties and following them for several years are needed to validate the accuracy of serum AMH concentration for the prediction of menopause in young women,” said Ramezani Tehrani.
The AMH test is already commercially available and clinicians advise it in case of assisted reproduction, said Rao. “It is not only inexpensive, but also throws useful data,” she added.
Source: The Telegraph (Kolkata)