There is no single test that directly measures egg quality. Unlike sperm, which can be examined under a microscope at any time, eggs are locked inside follicles and can only be visually assessed once they’re retrieved during an IVF cycle. What you can do is use a combination of blood tests, ultrasound measurements, age-based statistics, and physical signs to build a reliable picture of where you stand.
What “Egg Quality” Actually Means
When fertility specialists talk about egg quality, they’re primarily talking about whether an egg has the correct number of chromosomes. Every time an egg matures, it goes through a complex cell division process that must split 46 chromosomes into exactly 23. Errors during this division produce eggs with too many or too few chromosomes, a condition called aneuploidy. Aneuploid eggs either fail to fertilize, result in failed implantation, cause early miscarriage, or in rare cases lead to chromosomal conditions like Down syndrome.
The machinery that keeps chromosome division accurate degrades over time. The protein “glue” holding chromosomes together weakens, the cellular structures that pull chromosomes apart become less reliable, and the energy-producing components inside the egg (mitochondria) become less efficient. This is why age is the single strongest predictor of egg quality, even though it’s not something a blood test can capture.
Age and Aneuploidy Rates
The relationship between age and chromosomal errors in eggs is steep and well documented. In your mid-20s, roughly 20 to 25% of eggs are aneuploid. By 35, that number climbs to around 35 to 40%. At 40, more than half of eggs carry chromosomal errors, and by 45, the vast majority do. This is the central reason fertility drops sharply after 35 and why age remains the most important piece of information in any egg quality assessment.
These are population averages. Individual variation exists, which is exactly why the tests below matter. A 38-year-old with strong test results may have better reproductive potential than a 33-year-old with poor ones.
AMH: The Most Useful Blood Test
Anti-Müllerian hormone is produced by the small follicles in your ovaries, so the amount circulating in your blood reflects how many eggs you have left. It can be drawn on any day of your cycle, which makes it convenient. General reference ranges, according to Cleveland Clinic, look like this:
- Average: 1.0 to 3.0 ng/mL
- Low: Under 1.0 ng/mL
- Severely low: Around 0.4 ng/mL
AMH declines naturally with age. A level of 3.0 ng/mL is typical at 25, dropping to about 2.5 at 30, 1.5 at 35, 1.0 at 40, and 0.5 at 45. These are lower-end estimates for each age, so your result should be interpreted relative to your age bracket, not just against a single cutoff.
One important distinction: AMH tells you about egg quantity (ovarian reserve), not quality directly. A low AMH means fewer eggs are available, which reduces your chances per cycle and limits options if you pursue IVF. But a normal AMH doesn’t guarantee chromosomally normal eggs, particularly as you get older. Think of it as measuring the size of the pool you’re drawing from.
FSH and Estradiol on Day 3
Follicle-stimulating hormone, measured on day 3 of your menstrual cycle, reflects how hard your brain has to work to stimulate your ovaries. When your ovarian reserve is declining, your body compensates by producing more FSH. A day 3 FSH above 10 IU/L is considered elevated and suggests diminished reserve. In studies comparing groups, women with strong ovarian reserve had day 3 FSH levels around 5.0 IU/L, while those with elevated levels averaged 12.0 IU/L.
Estradiol is often tested alongside FSH because an abnormally high early estradiol level can suppress FSH and mask what would otherwise be an elevated reading. If your day 3 estradiol is high but your FSH looks normal, the FSH result may be falsely reassuring. The two tests work best as a pair.
FSH has a notable limitation: it can fluctuate from cycle to cycle. A single normal reading doesn’t rule out declining reserve, but a single elevated reading is meaningful. AMH has largely replaced FSH as the preferred first-line test because it’s more stable and can be measured any day of the cycle.
Antral Follicle Count on Ultrasound
An antral follicle count uses transvaginal ultrasound, typically done early in your cycle, to count the small resting follicles visible on each ovary. This gives a direct snapshot of how many eggs are potentially available for that cycle.
The numbers that matter: an AFC above 13 is associated with significantly better outcomes. In fertility studies, women with an AFC above 13 had clinical pregnancy rates of 66%, compared to 37% for those below 13. An AFC of 10 or below is a strong signal of diminished reserve, with a sensitivity of 75% for predicting a cancelled IVF cycle due to poor response. Counts below 12 are generally considered the threshold for predicting a poor response to ovarian stimulation.
Like AMH, AFC measures quantity rather than quality. But the two are closely related in practice: fewer follicles means fewer eggs to work with, which means fewer chances for a chromosomally normal egg in any given cycle.
Your Menstrual Cycle as a Clue
A shortening menstrual cycle can be an early, no-cost signal of declining ovarian reserve. A large systematic review found that women with short cycles (21 to 27 days) had AMH levels approximately 1.3 ng/mL lower and about 5 fewer antral follicles compared to women with normal-length cycles (28 to 31 days). Their natural fertility was about 19% lower per cycle, and in IVF, about 1.8 fewer eggs were retrieved on average.
If your cycles have been gradually getting shorter over the past year or two, particularly if they’ve dropped below 25 days, that’s worth mentioning to your doctor. The shortening reflects a faster progression through the follicular phase, which happens when fewer follicles are competing and the dominant one matures more quickly. It’s a subtle sign, but a meaningful one, independent of age.
What IVF Reveals About Individual Eggs
The only way to directly assess an egg’s quality is during IVF, when embryologists can examine it under a microscope after retrieval. A healthy, mature egg has a spherical shape, a uniform outer shell (called the zona pellucida), clear cytoplasm without dark spots or clumps, and an appropriately sized polar body.
Embryologists look for specific red flags. Eggs that are abnormally large (giant oocytes) or have an oversized polar body carry a high risk of chromosomal abnormality and are typically excluded from use. Clusters of smooth endoplasmic reticulum inside the egg are another serious concern. Vacuoles (fluid-filled bubbles in the cytoplasm), dark granular areas in the center of the egg, and an unusually thick outer shell (greater than 20 micrometers) are all associated with lower fertilization and implantation rates. Some eggs appear brownish with a thick shell and grainy interior; these so-called “brown eggs” are a known sign of poor quality.
If you’re going through IVF, your clinic will grade your eggs and embryos. But for most people trying to understand their fertility, the blood tests and ultrasound markers described above are the practical starting point.
CoQ10 and Egg Quality Support
Coenzyme Q10 is the supplement with the strongest evidence for supporting egg quality, particularly mitochondrial function inside the egg. It helps the cellular energy systems that power chromosome division, which is exactly the process that breaks down with age.
Clinical research suggests a dose of 200 mg per day for women with normal ovarian reserve, started at least 30 to 35 days before attempting conception or beginning an IVF cycle. For women with diminished ovarian reserve, a higher dose of 600 mg per day (often split as 200 mg three times daily) taken for at least 60 days has shown better results in improving ovarian response. Studies using this higher dose in women under 35 with low AFC and low AMH found improved outcomes during fertility treatments.
CoQ10 is not a reversal of aging. It won’t transform a 42-year-old’s eggs into those of a 30-year-old. But for women on the margin, particularly those with diminished reserve who are preparing for IVF, the evidence supporting its use is solid enough that many fertility clinics recommend it routinely.
Putting the Picture Together
No single number tells the full story. A thorough egg quality assessment combines your age (the strongest predictor of chromosomal normalcy), AMH level (best measure of how many eggs remain), antral follicle count (direct visual confirmation of reserve), day 3 FSH and estradiol (supporting data, especially if AMH isn’t available), and menstrual cycle patterns (a free, ongoing signal). Together, these create a profile that helps you and your doctor estimate your reproductive timeline, decide whether to pursue egg freezing, or understand what to expect from fertility treatment.