How Many Eggs Does a Woman Have

If you're thinking about your fertility now or in the future you’ve probably wondered: how many eggs do I actually have? The answer is both fascinating and a little sobering. While every woman is born with millions of eggs, that number begins to decline before you even take your first breath.

Here’s what you need to know about your ovarian reserve, how it changes with age, and what it could mean for your reproductive timeline.

You’re Born With All the Eggs You’ll Ever Have

Unlike sperm, which is produced continuously throughout a man’s life, a woman’s eggs are finite. Females are born with all the eggs they will ever have, and that number only decreases over time.

• At around 20 weeks of gestation (while still in the womb), a baby girl has approximately 6 to 7 million eggs in her ovaries.

• By the time she’s born, that number drops to around 1 to 2 million.

• At puberty, she has about 300,000 to 500,000 eggs.

But only a small fraction of these eggs estimated to be around 300 to 500 will actually mature and be released during ovulation over a woman’s lifetime.

Egg Count Declines With Age

As you age, not only does the quantity of eggs decline, but so does the quality. Both are key factors in fertility. Here’s how the average egg count looks across the decades:

• In your 20s: Egg count is still relatively high, and egg quality is at its peak. Fertility is considered optimal.

• By age 30: Most women have around 12% of their original egg supply remaining.

• By age 40: That number drops to about 3%.

While it’s entirely possible to get pregnant later in life many women do the odds decrease significantly as both egg quantity and quality diminish. According to the American College of Obstetricians and Gynecologists (ACOG), fertility begins to decline more rapidly in your mid-30s.

Why Egg Quality Matters, Too

Even if you still have thousands of eggs at age 40, fewer of them will be genetically healthy. Egg quality refers to how likely an egg is to result in a healthy pregnancy. As women age, the risk of chromosomal abnormalities in eggs increases, which can lead to miscarriage or conditions such as Down syndrome.

For instance, the chance of conceiving within a year for a healthy woman in her early 20s is about 86%. That chance drops to around 36% by age 40.

Can You Measure Your Egg Reserve?

While there's no way to count exactly how many eggs you have left, certain tests can provide an estimate of your ovarian reserve:

• Anti-Müllerian Hormone (AMH): This blood test is considered one of the most reliable markers of ovarian reserve. Higher AMH levels generally suggest a higher egg count.

• Antral Follicle Count (AFC): This is done via ultrasound to count the number of follicles in your ovaries at a specific time in your cycle.

These tests won’t predict your fertility with complete accuracy, but they can help guide decisions about egg freezing, fertility treatments, or when to start trying to conceive.

What Happens to the Eggs That Aren’t Ovulated?

Most of the eggs a woman is born with never make it to ovulation. Each month, dozens of eggs begin the maturation process, but usually only one reaches full maturity and is released. The rest are naturally reabsorbed by the body in a process called atresia.

Fertility Preservation Options

If you're not ready for pregnancy but want to keep your options open, egg freezing (oocyte cryopreservation) is an increasingly common solution. This is often recommended before age 35, when egg quality is typically better. Frozen eggs don’t age, so they retain the quality they had at the time of freezing.

Supporting Your Reproductive Health

While you can’t increase your egg count, certain lifestyle choices may support reproductive health:

• Don’t smoke: Smoking accelerates egg loss and can damage egg quality.

• Eat a nutrient-rich diet: Focus on antioxidants, healthy fats, and whole foods.

• Manage stress and get regular exercise.

• Limit exposure to endocrine-disrupting chemicals found in plastics and some cosmetics.

The Takeaway

Women are born with all the eggs they will ever have, and this number steadily declines throughout life. By understanding how your egg count and quality change with age, you can make informed decisions about your fertility and family planning goals.

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