Janice is a 32-year-old woman who had irregular menstrual periods for six months and then saw her periods stop completely.
She felt otherwise well. She saw her doctor, who tested her hormone levels and reported back that she was menopausal—she had run out of eggs!
Janice is not alone in this scenario. Premature menopause occurs in approximately 1 percent of women; however, the reserve of the ovary, that is, the number of eggs it has left, may prematurely begin to decrease rapidly in a much higher percentage of women.
In women over the age of 35, the ovarian reserve begins to decrease exponentially compared to women who are younger. A decrease in the ovarian reserve means there are fewer eggs to grow and mature, and therefore fertility may decrease.
Women are born with a certain number of eggs. Unlike men, who continue to make sperm throughout most of their lifetime, women are unable to make more eggs than the 2 million that they are born with.
If a woman has tests that reflect low ovarian reserve and does not yet have children, she should be encouraged to consider having a family.
Each month, through a process called attrition, women lose eggs—hundreds each month. By the time of menopause, at an average age of 51, the ovary has completely run out of eggs.
Smokers, women with a family history of premature menopause, and women with autoimmune diseases may all be at risk of premature menopause.
Unfortunately, we are unable to prevent this process.
Tests for Egg Quantity
There are three tests currently available to measure the ovarian reserve.
One is an ultrasound, done at the beginning of a menstrual cycle (day 2 or 3), that counts the preantral follicles—small follicles less than 1 centimetre in size that hold the immature eggs—in the ovary. A number greater than five is a good prognostic for reserve.
The second is a blood test for the level of FSH, or follicle-stimulating hormone, done on day 2 or 3 of the cycle, when estrogen level is at the lowest.
Lower estrogen means a higher FSH level is needed to stimulate the follicles and enable the egg inside each follicle to grow and mature. A low ovarian reserve also means more FSH is needed to stimulate egg maturation. A high FSH level, over 15, is a poor prognostic sign for ovarian reserve, indicating a low reserve.
The newest test available is for the level of AMH, or antimullerian hormone, a hormone produced by the ovarian follicles. This blood test can be done on any day of a menstrual cycle. A low AMH level is a poor prognostic sign indicating low ovarian reserve.
This test is not readily available from labs and is done mainly in fertility clinics, and it is currently not covered by provincial health plans such as Ontario Health Insurance (OHIP).
Having a Family
If a woman has tests that reflect low ovarian reserve and does not yet have children, she should be encouraged to consider having a family. Women seeking fertility assistance who test for low reserve are often counselled to be more aggressive with their treatment.
Sadly, science still cannot make more eggs, change the destiny of the eggs women have, or predict what will happen to women as they age.
Women in their 20s should be encouraged to have at least one test of ovarian reserve if they are considering having a family in the future.
Dr. Fay Weisberg is a gynecology and infertility specialist with an active private practice and is Chair of Continuing Medical Education and Professional Development, Department of Obstetrics and Gynecology, University of Toronto. Her website is www.firststepsfertility.ca.