A Woman’s Eggs: Do They Have an Expiry Date?

The Journey of a Woman’s Egg

Women are born with millions of eggs divided between their two ovaries. However, only a few hundred thousand survive into adulthood—the rest naturally perish over time.

Throughout her reproductive years, dozens of eggs start developing every day, but typically only one egg matures each month, leading to ovulation. This means that the eggs a woman carries are as old as she is, and their number and quality gradually decline with age.

Key Tests to Assess Ovarian Health and Fertility

Doctors use several tests to understand a woman’s ovarian reserve—the quantity and quality of eggs remaining. The most common ones include:

1. Anti-Müllerian Hormone (AMH)
2. Eggs are stored in tiny fluid-filled sacs within the ovaries, called follicles. These follicles release AMH, which can be measured through a simple blood test.
   • The advantage of the AMH test is that it doesn’t depend on the menstrual cycle, so that it can be done at any time.
   • Lower AMH levels usually indicate a reduced ovarian reserve, which may reflect a decline in fertility potential.
3. Follicle-Stimulating Hormone (FSH)
4. Produced by the pituitary gland at the base of the brain, FSH stimulates the growth and development of ovarian follicles.
   • FSH levels are also measured through a blood test.
   • Higher FSH levels often suggest decreased ovarian reserve.
   • However, since FSH levels fluctuate during the menstrual cycle, it’s not always reliable as a standalone measure of fertility.
5. Antral Follicle Count (AFC)
6. AFC is an ultrasound-based test that counts the visible follicles in each ovary.
   • AFC results generally correlate well with AMH levels.
   • However, AFC can be more subjective, as results depend on the skill of the sonographer, whereas AMH testing is more standardised and objective.

What These Tests Mean for You

These investigations give doctors a snapshot of your ovarian reserve. This information helps them personalise fertility treatments and determine appropriate medication doses for assisted conception.

It’s important to remember that while these tests provide valuable insight into egg quantity and ovarian health, they cannot predict the likelihood of achieving a successful pregnancy. Lifestyle, overall health, and personal history also play crucial roles in fertility outcomes.