There’s no single test that directly measures egg health. Egg “quality,” which refers to whether an egg has the correct number of chromosomes, can only be assessed indirectly through age, fertility outcomes, or genetic testing of embryos after IVF. What you can measure is egg quantity (your ovarian reserve) and certain hormonal markers that give clues about your overall reproductive health. Understanding the difference between these two concepts is the starting point for evaluating where you stand.
Egg Quality vs. Egg Quantity
These two terms sound interchangeable, but they describe completely different things. Egg quantity is the number of eggs remaining in your ovaries at any given time. You’re born with 1 to 2 million eggs, and that number drops steadily throughout your life. Egg quality refers to whether an egg carries the right amount of DNA to produce a healthy embryo. No blood test or ultrasound can assess quality on an individual basis.
This distinction matters because having a high egg count doesn’t guarantee fertility. In a natural menstrual cycle, only one egg is ovulated. What matters most is whether that single egg is chromosomally normal. Studies have definitively shown that egg quantity does not predict the chance of conceiving naturally. A woman with a lower reserve can still ovulate a perfectly healthy egg, while someone with a high reserve may ovulate one with chromosomal errors.
How Age Affects Your Eggs
Age is the single strongest predictor of egg quality. Eggs sit in your ovaries for decades, and over time they become more prone to accumulating chromosomal imbalances. Even in your 20s and early 30s, roughly 25 to 30% of embryos formed from your eggs will have genetic errors. That proportion climbs to about 50% by ages 37 to 38, exceeds 70% by age 40, and reaches approximately 88% by age 44.
When an egg with the wrong number of chromosomes is fertilized, the resulting embryo usually can’t develop normally. Most of the time it simply doesn’t implant, which shows up as a negative pregnancy test. Sometimes it begins to implant and then stops growing, which is the most common cause of miscarriage. This is why fertility declines with age even when egg quantity remains reasonable.
Tests That Measure Ovarian Reserve
While you can’t test egg quality directly, several tests give your doctor a picture of how many eggs you have left and how your ovaries are functioning. These are typically done early in your menstrual cycle, around day 2 or 3.
AMH (Anti-Müllerian Hormone)
AMH is a blood test that reflects the number of small follicles remaining in your ovaries. It can be drawn at any point in your cycle. Typical ranges shift with age: women aged 20 to 25 generally fall between roughly 10.6 and 55.6 pmol/L, while women aged 41 to 45 range from about 0.9 to 41.3 pmol/L. By ages 46 to 50, the range drops dramatically to 0.14 to 5.1 pmol/L. A result that’s low for your age suggests a smaller remaining egg supply, though it says nothing definitive about the quality of the eggs you do have.
Antral Follicle Count (AFC)
This is a transvaginal ultrasound done in the first few days of your cycle. The technician counts all visible follicles measuring 2 to 10 mm across both ovaries. A total count above 13 is generally associated with a good ovarian response and higher pregnancy rates. Counts of 10 or below are linked to lower pregnancy and live birth rates and a greater chance of poor response to fertility medications. An AFC of 9 or fewer has a specificity of nearly 84% for identifying a poor ovarian response.
Day 3 FSH and Estradiol
FSH (follicle-stimulating hormone) is measured on day 3 of your cycle. Higher levels suggest your brain is working harder to stimulate your ovaries, which can indicate a declining reserve. An FSH of 10 mIU/mL or above is associated with shorter menstrual cycles and earlier ovulation. Estradiol, measured on the same day, should ideally be below 80 pg/mL. Women with day 3 estradiol at or above 80 pg/mL have significantly lower pregnancy rates during IVF and higher cycle cancellation rates, even when their FSH looks normal. When estradiol reaches 100 pg/mL or above, no pregnancies were achieved in one study, and the cancellation rate hit 33%.
Cycle Changes That May Signal Declining Reserve
Your menstrual cycle can offer early clues. Research tracking over 1,800 cycles found that women with low AMH levels (below 1.6 ng/mL) had cycles that were about one day shorter on average than women with normal levels, and they ovulated earlier in their cycle. These women had roughly 1.6 times the odds of having short cycles. Similarly, women with elevated FSH had cycles about 1.1 days shorter.
Cycles that gradually become shorter, particularly dropping below 21 days, may be a sign of ovarian aging. This pattern occurs more frequently as menopause approaches. If your periods have noticeably shortened over the past year or two, it’s worth having your ovarian reserve markers checked, especially if you’re planning to conceive.
Lifestyle Factors That Support Egg Health
Diet
A Mediterranean-style diet, rich in fruits, vegetables, whole grains, and olive oil, has the strongest evidence behind it. Multiple studies on women undergoing IVF found that higher adherence to this eating pattern was associated with nearly double the clinical pregnancy rate and more than 2.5 times the live birth rate in women under 35. The benefits likely come from the diet’s high antioxidant content, which helps reduce oxidative stress on developing eggs. Women with low adherence to this diet had a significantly higher risk of unexpectedly poor ovarian response during fertility treatment.
CoQ10 Supplementation
CoQ10 supports the energy-producing structures inside your cells, which eggs depend on heavily during maturation. Several clinical studies have tested daily doses ranging from 180 mg to 1,200 mg, with most using 600 mg per day for at least two months before conception attempts. At 600 mg daily for two months, young women with poor ovarian reserve retrieved roughly double the number of eggs, had higher fertilization rates (67.5% vs. 45.1%), and produced more high-quality embryos. Even lower doses of 180 mg daily improved follicle development when used alongside ovulation-stimulating medications.
Environmental Exposures to Minimize
Certain chemicals in everyday products can interfere with egg development. BPA, found in some plastics and can linings, alters DNA patterns in developing follicles and reduces egg quality. Phthalates, common in fragranced personal care products, decrease antral follicle counts and disrupt normal follicle growth. Pesticide residues like DDT and its breakdown products interfere with hormone production in the cells surrounding your eggs, which can lead to follicle death or chromosomal errors in the egg itself. Choosing BPA-free containers, unscented products, and thoroughly washing produce are practical ways to reduce your exposure.
What These Tests Can and Can’t Tell You
Ovarian reserve testing gives you a snapshot of quantity and hormonal function, not a fertility verdict. A woman with low AMH can still conceive naturally if the egg she ovulates that month happens to be chromosomally normal. Conversely, excellent test results don’t guarantee that any given egg will be healthy. The only way to assess the chromosomal status of a specific egg is through preimplantation genetic testing of embryos created during IVF, which tests the embryo after fertilization rather than the egg itself.
If you’re considering these tests, the most useful approach is combining AMH, AFC, and day 3 bloodwork together rather than relying on any single number. Taken as a set, they give a much clearer picture of your ovarian reserve and help guide decisions about timing, whether that means trying to conceive now, considering egg freezing, or pursuing fertility treatment.