Infertility and Age: The Effects of Age on Ovarian Reserve and Infertility
Perhaps the greatest enemy to female fertility is increasing age. “Reproductive life” begins with the first menstruation and culminates in the menopause where few, if any, viable eggs remain. Many women delay childbearing until they have established their careers and are marrying at older ages. Unfortunately, the societal clock and biological clock are not always in “sync”. These delays in childbearing are partially responsible for the increased incidence of infertility related to age..
Infertility in “younger women” is defined by the American Society for Reproductive Medicine as the inability to achieve pregnancy after one year of regular, unprotected intercourse. In women aged 35 or older, the time is often shortened to six months. Women in their mid-late thirties should not delay seeing a reproductive endocrinologist/ fertility specialist as fertility is directly correlated with age and can decline very rapidly.
A woman is born with more than enough eggs for her reproductive lifetime. In a normally ovulating female, each month one, or more, of these eggs are recruited and develop under the influence of FSH.
Unfortunately, some women experience menopause at an early age, a condition known as premature ovarian failure. When the ovaries are releasing eggs that have diminished capability to fertilize and develop normally, the condition is termed “diminished ovarian reserve.” The ovaries, and therefore the eggs within them, can also be damaged by cancer, cancer chemotherapy, radiation, severe pelvic infections, or rarely women are born without one or both ovaries.
One measure of ovarian reserve is the level of FSH measured on day 3 of the menstrual cycle. An elevated level (>10) may be an indication of diminished ovarian reserve. The Clomiphene Citrate Challenge Test (CCCT) is administered to women at risk for elevated FSH levels to help “predict” their chances of success with IVF. An abnormal CCCT test (FSH >12) means there is a poor prognosis for IVF success. FSH levels >20 predict almost a 0% chance for conception using the woman’s own eggs.
Different laboratories use various methods for measuring FSH so it is important to use a laboratory that your infertility specialist is familiar with when FSH testing is being done.
Recently another test has been shown to be useful for evaluating ovarian reserve. Anti-mullerian hormone (AMH) or müllerian inhibiting substance (MIS) is a blood test that can be obtained at any time during the menstrual cycle. It can also be tested while a woman is taking oral contraceptives. As ovarian reserve decreases so does the AMH/MIS result while FSH usually rises. It is a useful adjunctive test when the FSH results are confusing or inconsistent. This is a test that is usually done in a regional laboratory that specializes in infertility testing. Results between 0.7 and 3.5 are usually considered to be in the normal range. Levels less than 0.7 suggest decreasing ovarian reserve. Levels above 3.5 can be indicative of polycystic ovarian syndrome. See http://www.repromedix.com for additional details .
Prior to IVF, women with ovarian disease had no treatment options. With today’s technologies, pregnancy can often be achieved using an egg donor (See the section on our Donor Egg Program). Egg donors are younger and are carefully screened using many physiologic and psychological tests. If a donor’s eggs are used in an IVF cycle with the husband’s sperm, the success rates usually coincide with the donor’s age, and are typically high (>50% delivered pregnancy rate if 2 good embryos are transferred). In fact, successful pregnancies using donor eggs have been achieved in women in their fifties. The offspring will have the genetic makeup of the father and the egg donor.
There are new technologies on the horizon that may ultimately allow women to reliably freeze their eggs for use in future IVF cycles. If a woman underwent FSH ovulation induction, she could produce many eggs that could be cryopreserved for future thawing, fertilization and subsequent embryo transfer when she is older. Currently, only embryos are “sturdy enough” to be consistently frozen, thawed and successfully implanted in the future. Problems with egg freezing will have to be overcome. These include the tendency of the egg’s cytoplasm to form ice crystals upon freezing which causes damage to the egg. However, over 150 pregnancies have been created using frozen/thawed eggs. This is an active area of current research and if a patient needs to undergo chemotherapy or radiation therapy participation in this type of research should be considered.
Reproductive Care Center, infertility clinic, features successful IVF and donor egg IVF programs. Our Web site has extensive information on the donor egg process, egg freezing, and embryo donation.
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