The Link Between Age and Egg Count in Women

From birth to menopause, your egg count and fertility naturally shift—here’s what to know and when to take action.

Every woman is born with a finite number of eggs typically between 1 and 2 million. But by the time puberty arrives, that number drops to around 300,000. As the years go by, both egg count and quality continue to decline, affecting fertility and reproductive options. Understanding how egg count changes with age can empower you to make more informed decisions about your health, fertility planning, and even family-building options.

Egg Count Over Time: What’s Normal?

Eggs are stored in the ovaries in structures called follicles. Each month, one follicle matures and releases an egg during ovulation. While this process is essential for fertility, it also depletes the ovarian reserve over time.

Here’s how egg count typically changes with age:

  • At birth: 1–2 million eggs

  • At puberty: Around 300,000 eggs remain

  • In the 30s: Fertility begins to decline gradually

  • By age 37: Egg loss accelerates, and egg quality also drops sharply

  • By age 50: Fewer than 1,000 eggs typically remain

This natural decline doesn’t mean pregnancy is impossible as you age, but it can be more challenging and may require additional support or intervention.

Egg Quantity vs. Quality

Both the number of eggs (quantity) and their health (quality) matter for fertility. While quantity affects how many eggs are available, quality influences whether an egg can develop into a healthy embryo. With age:

  • Egg quality declines faster than quantity

  • Older eggs are more likely to have chromosomal abnormalities, increasing the risk of miscarriage or IVF failure

  • Success rates for natural conception and fertility treatments drop after age 35 and again more steeply after 40

What Influences Egg Count and Quality?

Several factors can accelerate or impair egg health beyond age alone:

  • Autoimmune or genetic conditions

  • Environmental toxins and radiation

  • Cancer treatments, including chemotherapy

  • Smoking and excessive alcohol use

  • Low or high body weight

  • Chronic stress or hormonal imbalances

  • Previous ovarian surgeries

Some of these are within your control like lifestyle habits while others, such as genetics, are not.

How Egg Count Is Measured

Fertility specialists use various tests to assess ovarian reserve the number of eggs remaining in the ovaries. While none of these can guarantee your chances of conception, they offer valuable insights, especially for those planning for the future.

  • AMH (Anti-Müllerian Hormone) test: Measures hormone levels linked to the number of developing follicles. Higher levels typically indicate better egg supply.

  • Antral Follicle Count (AFC): Uses ultrasound to count small follicles in the ovaries. A higher count generally suggests a higher ovarian reserve.

  • FSH (Follicle-Stimulating Hormone) test: Elevated levels may signal decreased ovarian reserve, particularly when measured on day 3 of your cycle.

  • Estradiol (E2): High levels can mask elevated FSH, so it’s often measured alongside FSH for clearer insights.

  • Clomiphene Citrate Challenge Test (CCCT): An older method that assesses ovarian function by measuring FSH before and after taking a fertility drug.

These tests are especially useful if you’re considering egg freezing, IVF, or facing medical treatments that could affect fertility.

Fertility Options to Consider

Whether you're thinking about getting pregnant now or in the future, it's helpful to know your options:

  • Egg freezing (oocyte cryopreservation) for future use

  • Egg donation if egg quantity or quality is significantly reduced

  • IVF, IUI, or other fertility treatments

  • Preimplantation genetic testing (PGT) to assess embryo health

  • Lifestyle improvements, such as quitting smoking, managing weight, and reducing alcohol

  • Fertility preservation before cancer treatment

  • Financial planning, as fertility treatments can be costly and often aren't fully covered by insurance

  • Emotional support, including counseling to navigate complex decisions

When to Talk to a Healthcare Provider

It’s wise to consult with a fertility specialist or OB-GYN if you:

  • Have been trying to conceive for over a year (or six months if you're over 35)

  • Have irregular or missed periods

  • Have a family history of early menopause

  • Are considering fertility preservation

  • Are about to begin medical treatments known to affect fertility

The Bottom Line

Women are born with all the eggs they'll ever have, and both the number and quality of those eggs naturally decline with age. After age 37, that decline becomes more significant and by menopause, egg reserves are nearly depleted. While this is a normal part of aging, it’s important to be aware of your fertility timeline and options.

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