The “average” number of eggs in your ovarian reserve depends on age.

Your own eggs were formed while you were still in utero. In other words, you’re born with all the eggs you’ll ever have. From there, your egg reserve decreases over time. During fetal life, there are about 6 million to 7 million eggs. From this time, no new eggs are produced. At birth, there are approximately 1 million eggs; and by the time of puberty, only about 300,000 remain. Of these, only 300 to 400 will be ovulated during a woman’s reproductive lifetime. Fertility can drop as a woman ages due to decreasing number and quality of the remaining eggs.

These are the average number of eggs you have at each age:

• 20 weeks of gestation: 6 to 7 million oocytes
• birth: 1 to 2 million oocytes
• puberty: 300,000 to 500,000 oocytes
• around age 37: roughly 25,000 oocytes
• around age 51, the average age of menopause, roughly 1,000 oocytes

While those with diminished ovarian reserve have fewer eggs than those who without, there’s no clear consensus on the average number of eggs for those with the condition.

Diminished ovarian reserve is generally defined by hormone levels and not by the number of eggs in the ovarian reserve, which makes the definition of the condition confusing.

Since diminished ovarian reserve is diagnosed by blood tests measuring hormone levels, and not by counting eggs, it’s hard to determine the average number of eggs of someone who has the condition.