What is ovarian reserve testing?
Ovarian reserve testing checks a woman's eggs and her ability to become pregnant. Ovarian reserve testing usually consists of:
- Several blood tests for hormones on day 3 of the menstrual cycle: AMH, or anti-Mullerian hormone, FSH, estradiol, inhibin.
- A sonogram to check the ovaries (antral follicle count)
The bottom line of ovarian reserve tests
- Regardless of the results of ovarian reserve testing, attempting conception or pursuing fertility preservation at a younger age (in particular, at <35 years of age) is associated with better outcomes.
- Ovarian reserve tests predicts ovarian response during IVF.Only to a far lesser extent, they might predict birth outcomes from IVF. These tests have not, however, been shown to predict spontaneous pregnancy without IVF.
- Ovarian reserve tests should be administered for those situations listed below. Counseling beforehand regarding their limitations is suggested.
- Abnormal ovarian reserve test results do not necessitate IVF or other assisted reproductive methods. They may prompt a patient to accelerate her reproductive timeline and consult with a reproductive endocrinologist to consider her age and health-related risks of infertility or pregnancy loss.
Who needs ovarian reserve testing?
The following are candidates for ovarian reserve testing:
- Family history of early menopause (under 46 years of age)
- Before assisted reproductive technology (ART eg insemination, IVF)
- High risk of diminished ovarian reserve (eg chemotherapy, prior adnexal surgery, smoker)
- Certain medical conditions associated with diminished ovarian reserve:
- Ovulation issues: Anovulation or oligo-ovulation
- Women interested in fertility preservation
Measuring Egg Quality
Egg quality cannot be determined by looking at the egg, measuring its receptiveness to fertilization, or observing initial embryo division. Just because an embryo looks good in the lab, doesn't mean that it will implant.
However, some of the contributing factors leading to embryo implantation failure are:
Almost one in ten women who come in for infertility evaluation have such poor ovarian function that they are extremely unlikely to get pregnant. At the current time, this problem cannot be fixed. Therefore, a thorough assessment of egg quality through ovarian reserve testing is the most important fertility test that a physician does.
Women have all the eggs they are ever going to have in their lives before they are born. By the time of birth, the ovarian reserve — the number of remaining eggs stored in the follicles — has already decreased dramatically. For the rest of her life, ongoing follicular depletion will reduce the number of eggs remaining in the ovaries. In fact, far more eggs will be lost by degeneration than are lost by ovulation.
Testing of ovarian reserve may also give you an idea of your reproductive lifespan and timing of menopause, as well as diagnose PCOS. Women who are on birth control (and therefore not really ovulating) are told to go off birth control for several months before the test.
Ovarian reserve testing is not the same thing as testing for ovulation. A woman can ovulate normally and have very regular menstrual cycles and still have a low probability of becoming pregnant.
Tests of ovarian reserve are only predictive of fertility when they come back abnormal. A normal test does not mean that the ovaries work well. It just means that no test has yet demonstrated that they work poorly. These tests do not find all women with poorly functioning ovaries.
How Ovarian Reserve Testing Works
A test to check your ovarian reserve usually involves a vaginal ultrasound and blood tests to measure hormone levels, which must be conducted when a woman is menstruating (usually cycle day 3).
Between the ultrasound and blood tests, a doctor can determine how many eggs you might be able to grow in one round with the help of hormones. While a 21-year-old woman might grow 30 to 40 eggs in one round, by age 40, that number drops to six or eight eggs. The older you get, the harder it becomes to produce eggs.
Bear in mind that having a low ovarian reserve now does not necessarily predict your pregnancy chances for the future; it simply predicts how many eggs you can grow now. Some women may have a low ovarian reserve but then conceive naturally.
Follicle Stimulating Hormone Test
The FSH or follicle stimulating hormone test is done on cycle day 3. If you have elevated FSH levels on cycle day 3 you likely have diminished "ovarian reserve," which means the ovary is producing less feedback signal to the pituitary gland, and the body responds by making more FSH in an effort to stimulate the ovary.
Women with elevated FSH levels have markedly decreased egg quality and rarely conceive with their own eggs (they do, however, become pregnant readily with donor eggs). The precise physiological reason for this is unclear. However, we do know that when eggs are obtained from women with elevated FSH levels, they appear normal, they fertilize normally, and undergo initial embryonic cleavage at a normal rate. However, they rarely divide beyond the 8 cell stage and almost never implant.
Anti-Mullerian Hormone Levels
A newer test to check ovarian reserve is the anti-mullerian hormone or AMH test. This hormone is secreted by cells in developing egg sacs (follicles). The level of AMH in the blood is generally a good indicator of ovarian reserve.
Women have all the eggs they are ever going to have in their lives before they are born. An AMH test gives us some insight into the remaining quantity of eggs and number of fertile years you may have, but it cannot tell us much about the quality of those eggs. AMH does not change during your menstrual cycle, so the blood sample can be taken at any time of the month — even while you are using oral contraception.
Antral Follicle Count Test
This test involves a sonogram (ultrasound) test. Your doctor counts the number of 2-9 mm diameter antral follicles that can be seen with transvaginal ultrasound which gives a good idea about a woman's ovarian reserve.
Are normal results reassuring?
Normal test results do not necessarily mean that a woman will have an easy time conceiving. Or that she will have no problems in the future. It only provides information at the time of testing. Normal findings on ovarian reserve testing suggests that a woman might have a normal (that is, commensurate with age-matched peers) number of eggs in her ovaries. Similarly, abnormal results do not mean that she will have difficulty conceiving.
Do abnormal results mean the IVF is neded?
No. Individual results mean different things for different people and situations. A consultation with a fertility specialist is needed to find out what to do next.
The American Society for Reproductive Medicine states, “evidence of [diminished ovarian reserve] does not necessarily equate with inability to conceive” and “there is insufficient evidence to recommend that any ovarian reserve test now available should be used as a sole criterion for the use of ART.”
In a published study of 750 women attempting pregnancy, women with a low AMH level (<0.7 ng/mL) or high FSH level (>10 mIU/mL), or both, did not have a significantly lower likelihood of achieving spontaneous pregnancy within 1 year, compared with women with normal results of ovarian reserve testing.
I am not ready to get pregnant now. Should I freze my eggs?
If you are interested in seeking fertility preservation and ART, earlier referral to a reproductive specialist to discuss risks and benefits of oocyte or embryo cryopreservation is always preferable. The younger a woman is when she undergoes fertility preservation, the better. Among women planning to delay conception, each one’s decision is driven by her personal calculations of the cost, risk, and benefit of egg or embryo freezing—a picture of which ovarian reserve testing is only one piece.
Advanced Maternal Age
Even if FSH levels are normal, the age of the woman providing the eggs plays a major role in determining egg quality. Just as with women with elevated FSH levels, eggs obtained from women in their late 40's appear normal, fertilize normally, and undergo initial embryonic cleavage in a normal manner. However, such embryos almost never implant. Because of low implantation rates in women over 45 years old, normal FSH levels are not considered "reassuring."