As women age, it becomes more difficult for them to have a child. By age 40, many women are infertile, and by age 45, very few women will be able to have a successful pregnancy. This occurs as a result of a decline in both the quality and quantity of eggs remaining in the ovaries. The number of eggs gradually decline throughout life, and this decline accelerates beginning around age 35. Age is the best indicator of egg quality. The decreasing quantity of eggs in the ovaries is called “decreased ovarian reserve.” Women begin to lose ovarian reserve before they become infertile and before they stop having regular periods.
There are medical tests for ovarian reserve including hormonal levels (FSH and AMH) or ultrasound imaging of small follicles in the ovaries (antral follicle count). These tests do not absolutely indicate whether pregnancy is possible, but can give information about whether fertility treatments are likely to be successful. Women with poor ovarian reserve have a lower chance of becoming pregnant than women with normal ovarian reserve in their same age group.
Women who wish to delay childbearing until their late 30s or early 40s may consider fertility preservation. Women who are infertile with mildly decreased ovarian reserve may still be successful with fertility treatments. For women with a severely reduced ovarian reserve, the fertility treatment with the highest success rate involves the use of eggs or embryos donated by a younger woman. Using donated eggs or embryos, the chance of successful pregnancy is high and is based on the age of the donor.