Updated by the Progyny Clinical Team — July 2025.
Egg quantity and quality impact your ability to conceive and determine how your body responds to fertility treatment. Egg quantity is also known as ovarian reserve. Age plays a major role in both egg quality and quantity, with the number and quality of eggs decreasing over time. This is known as reproductive aging.
How age impacts fertility
Eggs are at their highest number before you’re born. At birth, you have about 1 to 2 million eggs. By puberty, only about 300,000 to 500,000 are left. Between puberty and menopause, most people ovulate about 400 to 500 eggs.
Fertility does go down with age, but the timing is different for everyone. Egg quality is usually best from the mid-20s to early 30s. After that, both the number and quality of eggs start to drop, which can make it harder or take longer to get pregnant.
How are egg quality and miscarriage linked?
You’re more likely to ovulate an egg with genetic issues as you age, resulting in lower fertility and an increased risk of miscarriage. If a poor-quality egg is fertilized, the embryo might not attach to the uterus, or it may start to grow but stop developing later, leading to a miscarriage.
Regular periods don’t always mean good fertility
It’s a common myth that regular periods mean your fertility is fine. You can still have trouble getting pregnant if your eggs are low in number or low quality.
Tests to check your egg quantity
Unfortunately, there are no tests that directly measure egg quality. However, several tests exist to determine the quantity. Common tests include an evaluation of serum follicle-stimulating hormone (FSH) and estradiol levels, anti-Müllerian hormone (AMH) levels, and antral follicle count (AFC).
Follicle-stimulating hormone (FSH) test
FSH is a hormone produced by the anterior pituitary gland in the brain and stimulates a dominant follicle in the ovary to grow and secrete estradiol (estrogen).
High FSH levels may indicate the brain is trying to compensate for ovaries that are behaving older or that have few eggs. Since levels can vary from month to month, your fertility doctor may want to check this test over several months to best understand your ovarian reserve.
Estradiol test
A high level of estradiol (a natural estrogen hormone) at the start of your cycle can be a sign that your ovaries are working harder than usual. This can happen to people over 35 or those with a lower egg supply. High estradiol can also lower FSH levels, which might make FSH results look better than they really are. That’s why your doctor usually checks FSH and estradiol at the same time — to get a more accurate picture of your fertility.
Anti-Müllerian hormone (AMH) test
AMH is a hormone made by the cells around your eggs. It’s a reliable way to check how many eggs you have because it stays about the same throughout your cycle. So, it can be tested anytime. A higher AMH level usually means you have more eggs. As you get older, AMH levels go down, which can be an early sign that your egg supply is getting lower.
AMH has been mainly studied for use in vitro fertilization (IVF). It can predict how your body might respond to fertility medications and gives a good idea of how many eggs may be retrieved. There are less conclusive data and studies about the relationship between low AMH and the ability to get spontaneously pregnant.
Antral follicle count (AFC) test
AFC is the number of small follicles in the ovaries that can be seen on an ultrasound. It can be measured at any time during your cycle. While AFC can change from month to month, it helps your doctor estimate how many eggs might be retrieved during an IVF cycle.
What is diminished ovarian reserve (DOR)?
DOR means that the number of eggs is lower than expected, which can make it harder to get pregnant. Signs of DOR include high FSH levels, low AMH levels, low AFC, or a poor response to fertility medication during an IVF cycle.
Keep in mind that having DOR doesn’t mean pregnancy is impossible. It just may be more difficult.
Reproductive aging is the primary cause of DOR, but most of the time, the cause is unknown. Ovarian reserve can also be impacted by:
- Tobacco use
- Underlying medical conditions
- Prior ovarian surgery
- Systemic chemotherapy
- Pelvic radiation
- Certain genetic abnormalities
There are no universally agreed-on criteria for diagnosing DOR. So, it can be difficult to provide a prognosis. It might predict a diminished response to ovarian stimulation in an IVF cycle, but not necessarily an overall pregnancy rate.
What to know about reproductive aging and treatments
No treatment or supplement has been shown to stop the process of reproductive aging or increase the number of eggs you have. However, people with infertility due to DOR can often use assisted reproductive technology, such as IVF, to increase their chances of conceiving.
Finding out if you have DOR is an initial important part of a fertility evaluation, especially as more people seek fertility treatment later in their reproductive years. If you do have it, talk to your doctor about treatment options.
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Disclaimer: The information provided by Progyny is for educational purposes only and is not medical advice. Always consult a qualified healthcare provider for medical guidance.