What is Ovarian Reserve?

By Dr. Joe Massey, MD

Ovarian Reserve Testing

Ovarian reserve refers to the number and quality of eggs you have. Before initiating ovarian stimulation for IUI or IVF, your fertility specialist will want to predict the quantity of eggs your body will produce. Assessing ovarian reserve will allow prediction of the response to medication within a certain range. It is important for your IVF doctor to understand as much about your ovarian reserve as possible so they can create the appropriate protocol for your unique situation. While there are tests to assess your ovarian reserve, they are predictors and not always reliable. The real test is what happens in an IUI or IVF cycle.

Antimullerian Hormone (AMH)

The first ovarian reserve test measures your anti-Müllerian hormone (AMH). AMH blood testing measures a very tiny amount of hormone produced by the antral follicles, and it is usually around 1 ng/ml in people of reproductive age. Except in very young people, dramatically higher numbers such as AMH of 7 to 10 suggest polycystic ovaries. Although it is not always predictive, if the AMH is less than 1 ng/mL, the possibility of diminished ovarian reserve becomes a consideration regardless of the patient’s chronological age. About 30% of the time, the result is misleading, because there can be variation in the handling of samples as well as normal variation in the actual amount of the hormone from month to month.

Antral Follicle Count (AFC)

Another test uses ultrasound to count the number of antral follicles. They contain eggs which will be emerging in the next couple of months of ovulation. These are the follicles that are capable of responding to stimulation with oral or injectable medications for IUI or IVF. Measuring the number of antral follicles that are 10 mm in size or smaller is often more predictive than the AMH test. Women with antral follicle counts of five or fewer, or who showed previous low response to stimulation, are said to have low ovarian reserve or diminished ovarian reserve (DOR).

Follicle-stimulating hormone (FSH)

Although it is not necessary to test FSH, it is critical to test on days 2, 3, or 4 of the menstrual cycle. The FSH level becomes more important if the AMH level is low. A corresponding high FSH level can spell trouble. FSH can be from 2 to 10 mIU/mL. Any level over 10 mIU/mL is high and reflects low ovarian reserve. The higher it goes over 10, the greater the concern. Levels over 20 are an indicator of dramatically diminished outcomes from ovarian stimulation of any kind.

When FSH is tested, estrogen levels should be tested simultaneously. If the estrogen is high (50 pg/ml or less is normal), it may be another indicator of low ovarian reserve. Although relatively uncommon, sometimes the estrogen level is over 75 when the FSH is low, making it seem like ovarian reserve is good, but the estrogen is actually suppressing the FSH.

Past history of IUI or IVF

If a patient has been through drug treatment for IUI or IVF previously, their response becomes the standard for assessing her ovarian reserve. The best indicator of ovarian reserve is the number of eggs retrieved at IVF (5 to 15 is ideal).

Ovarian Reserve and IVF protocol

Age is the most critical component in determining the exact drug treatment protocol to be recommended for IVF. Because ovarian reserve is often independent of age, your fertility specialist team will take AMH, AFC, and any previous IUI or IVF cycles into consideration for your protocol. The best protocol for you, including the amount of drug used each day, will be tailored to your situation.

IVF Success

The success rate for IVF varies according to the individual patient. The sophisticated testing of the ovarian reserve discussed in this article can help define the chances for success for you. Generally speaking, younger people have more and better-quality eggs than older ones. After about age 32, fertility begins to decline, along with IVF success rates, which can decline dramatically in the late 30s and early 40s. However, all the estimates of IVF success are moderated by measures of ovarian reserve.

In Summary

In conclusion, your fertility doctor will investigate your ovarian reserve as part of your fertility work up. Having as much information as possible about this helps them to individualize your IUI or IVF protocol. This is also important for LGBTQ+ couples, especially if you have one partner in mind for the egg retrieval or are using a gestational carrier, both of whom will require testing to determine whether there is diminished ovarian reserve.

As a well-known pioneer in IVF, Dr. Joe Massey loves to share in the joy of helping build families. Dr. Massey’s achievements in fertility medicine include involvement in the first pregnancy in the world following assisted hatching in 1988 and in the world’s first pregnancy following intracytoplasmic sperm injection (ICSI) in 1993. He has led a number of clinical trials and co-authored many articles published in medical journals.