Reflecting the trend of delaying motherhood, soaring numbers of women are having egg counting tests to determine how fertile they are. In the past year, Dr. Amin Gorgy, a fertility consultant, claims to have seen a 200 per cent rise in women coming to his clinic to have the test. The test determines how many eggs a woman has left, called her “ovarian reserve.” This indicates how fertile she is and can detect any problems including polycystic ovary syndrome (PCOS) and blocked fallopian tubes.
The check-up involves two tests, which when combined, are the most accurate predictor of a woman’s store of eggs. The higher the number of normal eggs a woman has, the greater her chance of having a baby.
Egg counting was relatively unknown five years ago, but it is now exploding in popularity. Also interesting, is that more and more younger women are opting to have the test, with the average age falling from 37 to 38 five years ago to just 33 today.
“Women and girls are becoming more conscious of the risks, and they are more aware of the risks of declining fertility,” said Dr. Gorgy. “It has become more obvious from stories in the media that they can’t just wait until they’re 40.”
Amongst women of the same age, egg numbers and quality can differ dramatically. One woman may learn through having the test done that she can successfully delay motherhood, while another may discover that she should either start having children right away or consider freezing her eggs for later.
Most women are born with an average of two million eggs, which is all the eggs they will ever have in their lifetime. But every month a woman loses between 55 and 1,500 eggs a month. By the time a woman is of child-bearing age, she has just 300,000 left. By the time she is 30, the average woman has only 70,000 eggs remaining, which drops to 30,000 when she is 35 and 25,000 when she is 37.5. Once the remaining number of eggs falls to 25,000, the number lost per cycle increases at an even faster rate. When women hit menopause (the average age of which is 51 in the US and in the UK) they have only 1,000 eggs left, on average. While thousands of eggs seems like plenty to have a child, Dr. Gorgy explains that as a woman ages, the quality of her eggs declines dramatically, as does her fertility.
As a woman ages she loses thousands of her eggs, and the remaining ones suffer chromosomal damage and become abnormal. It is not fully understood why this is, although some scientists believe it is because the mitochondria degenerate and can no longer support the function of the egg. Others say it is because the egg cells suffer chemical damage which changes their DNA. When she is young, a woman has a higher proportion of normal eggs than abnormal ones, but this proportion changes as she ages, so that by the time she is 37.5, more of her remaining eggs are abnormal than normal. Higher quality eggs are released when a woman is young, he explains. An older woman, with lower quality eggs, has less chance of becoming pregnant, a higher risk of miscarriage, and a higher risk of having a child with an abnormality like Down’s syndrome.
Dr. Gorgy says, “The quality of a woman’s eggs is directly related to her age. Young women with low ovarian reserve are much more fertile than older women with the same ovarian reserve. This is because of the better quality eggs in younger women. The two things that predict success fertility is number of eggs and their quality,”he explained. “The egg counting tells us the number, the age tells us the quality.”
As to when women should have their eggs counted, it is recommended that woman have the test when they are in their 20s. Having the test at this age allows a woman to gauge more accurately just how much time she has before she should begin having children, and can catch any possible fertility problems that may exist.