While testing blood for FSH level is the easiest test, “there are lots of predictors of ovarian reserve, so we don’t always hang our hat on FSH,” says Dr. Rackow. A doctor may order additional blood tests, for example, to check levels of other hormones that can influence egg development and ovulation, or indicate ovarian reserve. Some women may be advised to have an ultrasound just after menstruation to get a count of the small, undeveloped follicles—called antral follicles—that are visible in the ovaries. From this, doctors can estimate the number of all remaining eggs.
When a woman younger than 40 finds out that her FSH is high and/or the number of her remaining eggs is low, there may be several possible reasons:
Medical treatment, such as
chemotherapy, radiation,
or ovarian surgery
This is probably the easiest cause to pinpoint. Chemotherapy or radiation to the pelvic area can damage existing eggs or speed up ovarian aging. Women facing these treatments can opt to freeze eggs or ovarian tissue ahead of time so that they have healthy eggs to use when they’re ready to be pregnant.
Premature ovarian failure (POF),
also known as primary ovarian
insufficiency (POI)
These terms simply mean that the ovaries have begun to stop functioning normally in a woman younger than 40. POI/POF can cause irregular or skipped periods, sometimes for years. The condition can result from genetic abnormalities in the X chromosome or from an autoimmune response, in which a woman’s own body attacks her ovarian tissue. But in many cases the cause is unknown. According to the book Before Your Time: The Early Menopause Survival Guide by Evelina Weidman Sterling, Ph.D., and Angie Best-Boss (Fireside, 2010), an estimated 1 to 4 percent of women may have this condition.
Women with POI/POF still have a small chance—estimated at around 10 percent over 10 years—of conceiving on their own. “If a woman has been diagnosed with low ovarian reserve but has not yet started skipping periods, there seems to be a window where aggressive hormone treatment may help her get pregnant quicker,” says Dr. Santoro. “By the time it has progressed to full-blown ovarian failure, where she may go six months without a period, there is no treatment proven effective to stimulate egg production, even for IVF (in vitro fertilization). We know the eggs are there, but we can’t find the magic bullet to treat them.” For women who don’t want to bet on those slim chances of conceiving naturally, the recommended choice is usually IVF.
