Doctors in Iran have developed a blood test to predict the age at which a woman will go through menopause.
The groundbreaking test, if proved reliable, will have a huge impact on the choices many women make about childbearing.
In late June 2010, Dr Fahimeh Ramezani Tehrani presented the results of a clinical trial of the test to the European Society of Human Reproduction and Embryology. The test measured the levels of anti-Müllerian Hormone, AMH, which is produced by cells in women’s ovaries. AMH controls the development of ovarian follicles which produce and release a woman’s oocytes (her eggs). The 266 participants, aged between 20 and 49, were tested three times over six years and their AMH levels were correlated with the ages at which they reached menopause.
Dr Tehrani’s research team found that the test predicted the date of menopause to within four months. Higher levels of AMH predicted later menopause than lower levels.
The significance of the test for women trying to decide when to start a family by natural methods is clear. Whatever the demands of a woman’s career, or whatever her financial or relationship situation, it can only be useful for women who want children to know when the menopause will put an end to their fertile years.
A woman uncertain about the number of fertile years she has left may decide to become pregnant at a difficult time in her relationship or career, feeling she has no choice. Equally, that uncertainty can give many women the false impression that they can delay pregnancy until their forties. It is not uncommon for a woman to stop using contraception in her late thirties or early forties, assuming she will get pregnant quickly, only to find nothing happens. High profile cases of singers and actresses who have children in their forties have contributed to the idea that having late babies is fairly easy. The reality for many women is quite different as they find their natural fertility has declined or ended.
If Tehrani’s menopause test proves accurate it will help give women greater control over their fertility. Imagine a young woman knowing she will continue to produce eggs until she is 45. She may decide to concentrate on her career in her thirties and delay starting a family until she is 39 or 40. Another woman, discovering she’ll go through the menopause at 40, will know she has different choices to make.
Although the average age of menopause is often said to be around 50, that statement can be dangerously misleading. Many women cease to menstruate much earlier. ‘Normal’ menopause can arrive from 45 onwards and ‘early menopause’, designated at any age before 45, can arrive much earlier, while a woman is in her thirties.
Dr Tehrani, of Tehran’s Shahid Beheshti University of Medical Sciences, believes that the blood test “could enable us to make a more realistic assessment of women’s reproductive status many years before they reach menopause. For example, if a 20-year-old woman has a concentration of serum AMH of 2.8 nanograms per millilitre, we estimate that she will become menopausal between 35 and 38 years old… 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.”
The blood test will now be used in a larger trial to determine its accuracy in predictiing menopause.
However, while the test may give useful information about menopause to many women, it cannot be per se a guarantee of fertility. A woman may continue to menstruate until she is 40 or even 50 but that does not mean she will necessarily be able to conceive. One study of women’s fertility available on PubMed found that “the incidence of anovulatory cycles increased markedly after age 40 and, concomitantly, the coital frequency steadily decreased.” While a woman may be able to control how often she has sex, she cannot conceive (without IVF) during a cycle which produces no egg.
Even where eggs are regularly produced, older women may have other problems conceiving and giving birth to a healthy baby. Fibroids and endometriosis can prevent conception for example. Older eggs can be harder to fertilise. A fertilised egg may fail to implant. Where implantation does occur, miscarriage and birth defects are more likely in the pregnancies and babies of older women.
Dr Tehrani also conceded that the test’s maximum margin of error was three to four years. For a women planning to delay pregnancy that’s a big margin of error. It’s not much use assuming you can become pregnant at 40 if you stop ovulating at 36.
The test promises to be particularly useful for women who will experience an early menopause. They will be forewarned that their fertile years are more limited than those of other women. That way, they’ll have the choice of having children while young or perhaps freezing eggs for use later in life. Women who discover their menopause will arrive after 45, however, should not assume that natural late conception will be easy.