Aging egg supply
From birth, females have a fixed—though plentiful—supply of eggs (ovarian reserve). As a woman ages past her mid-30s, her eggs gradually degrade, making it less likely that she will naturally conceive, or that an assisted reproductive technology (ART) procedure will result in pregnancy and a healthy baby.
Among American women in their 20s to mid-30s, over 35% give birth per ART cycle using their own eggs. As women age, the live ART birth rate gradually drops:1
- To about 20% per IVF cycle by age 39.
- To 2% or less per cycle in women over age 43. Many women over age 40 choose to use donor eggs, which greatly improves their chances of giving birth to a healthy child.
While there is no definitive test of ovarian reserve, a woman's follicle-stimulating hormone (FSH) level can be measured to evaluate how well her ovaries are working. A high FSH level is a sign that the body is trying to stimulate the ovaries to make more egg follicles, but the ovaries are not responding and conception is unlikely.
A woman's FSH level can be tested using a blood sample:
- Early in her menstrual period, around day 3.
- Before and after a clomiphene challenge test, early in her menstrual period.
| Author: | Bets Davis, MFA | Last Updated: April 7, 2006 |
| Medical Review: | Joy Melnikow, MD, MPH - Family Medicine Kathleen Romito, MD - Family Medicine Kirtly Jones, MD - Obstetrics and Gynecology | |
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