Fertility tests that claim to show a woman how close she is to midnight on the biological clock may be a waste of time, new research shows
The tests, which indicate how many egg cells a woman still has, don’t seem to do a good job in predicting which women will get pregnant. Women who seemingly had plenty of eggs left were no more likely to conceive over the next several months than women who seemed to be at the end of their supply.
The researchers, who were hoping for an easy test to help women plan families later in life, say they’re back to square one.
“I definitely was surprised by the findings,” said Dr. Anne Steiner, of the University of North Carolina, Chapel Hill, who led the study.
“Women that had signs of diminished ovarian reserve when their lab tests suggested they had a low number of eggs remaining, they were just as likely to get pregnant in six months or 12 months as a woman with a higher ovarian reserve.”
That means assumptions about what causes infertility may be incorrect, Steiner added.
Common medical wisdom holds that women are born with all the egg cells, or oocytes, that they will ever have. These mature, usually one by one, throughout a woman’s life. Most are reabsorbed by the body.
How many eggs are left is called “ovarian reserve” and by a woman’s late 30's, it’s usually pretty low.
Steiner’s team tested 750 women who were between 30 and 44 years old who had been attempting to conceive for three months or less.
The tests measured four hormones: antimüllerian hormone (AMH), follicle-stimulating hormone (FSH), and inhibin B.
A woman’s body produces less and less AMH and inhibin B as her lifetime supply of eggs cells runs out. Levels of FSH go higher as a woman nearing menopause ovulates.
“We kind of thought it would be a good fertility test,” Steiner said.
And before their study ended, companies had started selling over-the-counter products that measure the same hormones, and that claimed to tell women how many fertile years they had left.
But it appears they don’t do any such thing.
“After six cycles of attempting to conceive, results did not differ significantly between women with low levels and normal levels of anti-Müllerian hormone — a 65 percent chance of conception, compared to a 62 percent chance,” Steiner’s team wrote in a report published in the Journal of the American Medical Association.
“Similarly, results were not statistically different after 12 cycles: 82 percent versus 75 percent.”
Don't count on ovarian reserve
So, women trying to juggle work and career, or contemplating putting off having a family for other reasons, should not gamble by using one of these tests, Steiner said.
“Tests indicating high ovarian reserve should not be used as justification for delaying intent to conceive,” she said.
“Women at 35, 36, may say ‘oh, I have great ovarian reserve. I don’t have to freeze my eggs. I could wait three or four years because my egg count looks good’,” Steiner added.
But they shouldn’t. “Really, women should not be using these to assess their current reproductive potential,” Steiner said.
Instead, simple age may be a better predictor. Quality of both eggs and sperm decline with age.
“We still have plenty of things that cause infertility,” Steiner said. “Age is still a factor.”
Dr. Nanette Santoro of the University of Colorado School of Medicine said it’s also possible that women with a lower “ovarian reserve” are more likely to miscarry.
“Pregnancy outcomes beyond a positive pregnancy test result were unavailable. It is therefore possible that women with low ovarian reserve as defined in this study experienced more pregnancy loss and had lower live birth rates,” Santoro, who was not involved in the research, added in a commentary.
“We live in a world where patients place great faith in technology, and often request lots of tests from their doctor,” said Dr. Stuart Lavery, an expert in reproductive medicine at London’s Hammersmith Hospital.
“Steiner and colleagues have done women a great service in helping them avoid unnecessary cost and incorrect judgments around their natural fertility."
Other outside researchers said the study was solid. “The most important test is whether a woman is ovulating, i.e. whether she is releasing an egg every month, rather than how many eggs she might have in reserve,” said Dr. Richard Anderson, head of gynecology and obstetrics at Britain’s University of Edinburgh.