Egg Quantity vs. Egg Quality

Egg Quantity vs. Egg Quality

6 min read

When it comes to female fertility, it’s all about the eggs: Egg quality and egg quantity. But, it’s often easy to confuse how each metric affects overall fertility and the treatments that can help improve them. So, what’s the difference between egg quality vs egg quantity? And how does each impact fertility outcomes?

What is egg quality?

Egg quality refers to the health of your eggs. A healthy egg has 23 chromosomes and normal mitochondrial function (cell energy) and cytoplasmic factors (cell development). When all these boxes are checked, the egg is more likely to successfully fertilize, develop into an embryo and, ultimately, lead to a pregnancy and live birth. Abnormal eggs are less likely to make it through this process which can be a factor in infertility and miscarriage.

What affects egg quality?

Like most things in fertility, age is the biggest predictor of egg quality. The older you are, the more likely you are to have abnormal or poor-quality eggs. This doesn’t mean that all your eggs will be abnormal, but rather that statistics are no longer on your side (it’s why fertility declines, especially after age 35). As you age you have a smaller percentage of eggs that are normal, which means you may have to try for more cycles for that ideal egg to arrive. 

Because of the impact of aging on fertility, doctors generally recommend that you start trying to conceive as soon as you’re ready (though when it comes down to it, it’s not always that simple of a decision). It’s also why fertility doctors recommend freezing your eggs earlier rather than later if you’re interested in fertility preservation, because there’s a greater likelihood of getting multiple, healthy eggs for later use.

How do you test egg quality?

Unfortunately, other than using age as a guideline, there are no tests that can measure your egg quality (this is unlike with sperm, where tests can be done to assess various parameters of sperm health). It’s safe to assume that a successful pregnancy that leads to a healthy baby means it was a good-quality egg (and a good-quality sperm—it takes two after all). On the other hand, if you’ve been trying to conceive for a while without luck, or have experienced multiple losses, that can be a sign pointing to an egg-quality issue. 

Though there’s no preconception test that can tell you your egg quality, if you’re undergoing IVF, you can get insights into the quality of your embryos (which reflects both egg and sperm quality), either via visual embryo grading or biopsy of the embryo for PGT testing).  But even embryologists don’t have a visual egg scoring system to provide meaningful feedback on egg quality. 

How do you improve egg quality?

Even the most fertile person will, with age, experience a decline in egg quality. And you can’t turn back the clock or change your genetic makeup—but you can try to keep the eggs you have as healthy as possible. This starts with limiting behaviours (like smoking) and changing things within your control (like exposure to environmental toxins and managing your weight) that can speed up the aging process . 

There is a lot of evidence that eggs—like the rest of the body—benefit from a healthy lifestyle and antioxidant support. Specifically, Coenzyme Q10 (CoQ10) promotes growth and repair in your tissues and it’s a great fuel source for eggs (and sperm) which need lots of energy to function. As an antioxidant, it protects against cell and DNA damage that stems from smoke, pollution and stress. Bird&Be Power Prenatal for Females includes CoQ10 (along with other powerful ingredients like NAC and Trans-Resveratrol) to support healthy eggs as you try to conceive.

Read more about CoQ10, and why you need it if you’re trying to conceive →

What is egg quantity?

Egg quantity refers to the number of eggs you have left. You’re born with all the eggs you’ll ever have over your lifetime (if you’re female) and this number declines as you age. Each cycle, follicles (the sacs in your ovaries that hold eggs) are stimulated by a hormone called FSH, and one will grow to become the dominant follicle and release an egg. It takes just one egg (meeting up with one sperm and a healthy endometrium) to make a baby, so low egg quantity won’t impact your ability to get pregnant right now if you’re trying to conceive without intervention (since you usually only ovulate one egg at a time anyways). But, knowing your egg quantity can be helpful for planning your reproductive timeline (a lower count is associated with diminished ovarian reserve or early menopause, so you may want to start sooner) and helps doctors understand how receptive you might be to treatment (a higher reserve is linked to better IVF outcomes). Knowing your egg quantity can’t tell you how fertile you are (we all just release one egg per cycle unless undergoing fertility treatment), but the more eggs you have, the more chances you have, so it is an important consideration, especially if fertility treatment will be part of your journey.

What affects egg quantity?

No surprise here, age is the number one reason for declining egg count (or diminished ovarian reserve). Ovarian reserve decreases as you get older and while the rate of decline is different for everyone, we will all have fewer eggs at 35 than we did at 20. Outside of age and your genetic predisposition, there are other factors that can impact your ovarian reserve like direct harm to the ovaries (like ovarian surgery, chemotherapy and pelvic radiation) and lifestyle factors (smoking, environmental toxins, and obesity).

How do you test egg quantity?

There are a few ways you can determine ovarian reserve, including a follicle-stimulating hormone (FSH) test, an anti-mullerian hormone (AMH) test or an antral follicle count (AFC).

Read more about ovarian reserve and how to test it →

  • FSH Test: This can be done through a blood test (with a doctor’s requisition) or at home with a urine test. The higher the FSH when tested on day 3 of your cycle, the lower the ovarian reserve (learn more about FSH here). Bird&Be’s Ovarian Reserve Screening Test can flag rising FSH so you can better understand your ovarian reserve and get support sooner if needed.

  • AMH Test: AMH is a hormone secreted by developing follicles—the greater the number of follicles developing that cycle, the higher the AMH (and the higher the ovarian reserve). It’s always a blood test, usually requisitioned by your doctor.

  • Antral Follicle Count: By looking at the ovaries through ultrasound and counting the antral follicles (the number of small follicles recruited during a cycle) you can get an overall sense of the ovarian pool (the number recruited corresponds to the total number). The more antral follicles, the bigger the ovarian reserve.

How do you improve egg quantity?

Unfortunately, egg quantity can’t be improved—you get what you get. As mentioned, some lifestyle factors like smoking will increase that rate of depletion so avoiding them is important, but, there’s no way to stop the depleting egg count. Instead, if you’re diagnosed with diminished ovarian reserve, the treatment is about improving your egg quality to help you get pregnant ASAP or preserve (freeze) the eggs you have before they deplete further. .

What’s the difference between egg quality vs egg quality?

Egg quantity is how many, whereas egg quality is how healthy. Unfortunately, both decline as we age. While we can’t improve our count and have few options to really slow the rate of depletion, there are things we can do to help our egg health

Egg Quantity vs Egg Quality: A Summary

 What is it? Can it be tested? Can it be improved?
Egg Quantity How many eggs Yes Not really (but you may be able to adjust plans accordingly)
Egg Quality How healthy the eggs are No Yes

To support egg quality when trying to conceive (and even before, as eggs take about 3 to 4 months to develop), it’s a great idea to adopt healthy lifestyle habits. Meanwhile, if you have reason to believe that you have low ovarian reserve (such as elevated or high results on an FSH screening test), you might choose to adjust your timeline for trying to conceive  or see a doctor for diagnostic testing and guidance (remember, if you’ve been trying to conceive for a year—or 6 months if you’re 35 or older—without luck, it could be time to talk to a doctor). Quality is a critical factor no matter how you’re hoping to make a baby—and the good news is, it’s a bit more in your control.