What Does Having a Diminished Ovarian Reserve Really Mean?
By: Robert Colver, M.D.
Nov 26, 2018
A woman is born with all of the eggs she will ever have — typically between one and two million. As she gets older, she loses eggs. By the time she hits puberty and begins her menstrual cycle, she has roughly 300,000 left.
This loss will continue with age, becoming more rapid as a woman approaches menopause. Although 51 is the average age that menopause begins, it’s different for every woman, and sometimes her number of eggs can decline sooner than we would expect.
What is diminished ovarian reserve?
If the number of ovarian follicles — the fluid-filled sacs that house each egg — a woman has left is abnormally low, we call this having a diminished ovarian reserve.
Many women who are diagnosed with having a diminished ovarian reserve jump to the conclusion that this must also mean they have a decreased ability to have a baby. This is a common misconception.
Diminished ovarian reserve refers specifically to the quantity of follicles, not necessarily quality of eggs. A diminished reserve alone does not mean you will not be able to get pregnant naturally or with assisted reproduction. It does mean that the number of eggs available is decreased.
What causes this decrease in eggs?
There are several factors that can contribute to a diminished ovarian reserve. These can include:
- Significant alcohol use
- Previous ovarian surgery, such as to remove scar tissue or cysts
- Previous cancer treatment, such as radiation or chemotherapy
- Family history of early menopause
Sometimes, there is no clear explanation for an abnormally low reserve.
How do I know if I have a diminished ovarian reserve?
There are very few indicators or symptoms of diminished ovarian reserve. If you have had trouble getting pregnant — no success after a year of trying if you are under 35, or no success after six months if you are over 35 — we will often recommend testing to evaluate your reserve.
Noticeably shorter menstrual cycles (decreasing from 28 days to 21 days, for example) can indicate that you are getting closer to menopause, which also means your reserve is likely decreasing.
The only way to know for sure is to undergo testing. We evaluate a woman’s ovarian reserve by using a combination of tests that include:
- Day 3 Follicle Stimulating Hormone (FSH) and Estradiol blood test
- Antimullerian Hormone (AMH) blood test
- Antral Follicle Count (AFC) transvaginal ultrasound
We use results from all of these tests to get an accurate picture of a woman’s remaining follicles. The results of a single test may not tell the entire story.
It’s important to understand that while these results can help us see where you are in your reproductive timeline and help determine a course of action, they are not predictive of your overall ability to or likelihood of getting pregnant.
A diagnosis of diminished ovarian reserve, coupled with knowing your age and other fertility factors, can help us determine appropriate next steps.
What does it mean if my reserve is low?
If your test results show that your reserve is low, and you want to have children, you should talk with a fertility specialist, particularly if you are over the age of 35. A low reserve doesn’t mean you won’t be able to get pregnant, but that you probably don’t want to waste any time getting started.
After age 35, your reserve begins to naturally diminish more rapidly. In addition, the quality of your eggs begins to decline, with more and more of your eggs becoming genetically abnormal. Genetically abnormal eggs create genetically abnormal embryos, which cause an increased risk of miscarriage and birth defects.
At age 30, approximately 60 percent of embryos are normal, and 40 percent are abnormal. By age 36, this ratio shifts to 50/50. By age 40, only 30 percent of embryos are normal, with the majority being abnormal. (Genesis Genetics/CooperGenomics)
If there are additional factors at play, such as a history of endometriosis or low sperm count in your partner, we will likely want to expedite any fertility treatment, regardless of your age, in order to get the best possible outcomes.
What if my reserve is low, but I’m not ready to have kids yet?
Some women start to see a declining ovarian reserve at a young age or before they have found a life partner or are ready to have children. In these situations, fertility preservation is an option. This entails retrieving and freezing a number of your eggs now for use with assisted reproduction later if it is needed.
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