Age is the biggest factor in female fertility, as egg quantity and quality declines significantly after the mid 30s.
Eggs are produced in follicles within the ovaries and all the eggs that a woman will have in her lifetime are present when she is born. Immature eggs are released continuously and the rate of loss increases after the age of 35 and continues until about the age of 54 when no eggs are left and the woman will have a menopause.
Poor egg quantity may also be an issue for younger women when eggs have been damaged, perhaps by chemotherapy or surgery, or through an inherited genetic condition.
The follicles produce the hormone Anti-Mullerian Hormone (AMH), and the level of AMH is related to the pool of remaining eggs,
Women with many small follicles, such as those with polycystic ovaries, have high AMH hormone values, and women that have few remaining follicles and those that are close to menopause have low AMH levels. So an AMH test is commonly used to assess the number of eggs available and to predict response to ovarian stimulation.
This is not a measure of egg quality, however if more eggs are available there is a greater chance that one will be of sufficient quality.
Although AMH blood levels give an indication of the remaining egg supply – or “ovarian reserve” – as the release of eggs is not consistent the AMH reading should not be used to predict future fertility.
Symptoms of low egg quantity include: difficulty conceiving, recurrent miscarriage.
Diagnosis: a test for Anti-Mullerian Hormone (AMH), a substance produced by small ovarian follicles.
- IVF with own eggs
- IVF with donated eggs – success rates for older women with donated eggs are equivalent to those of women under 35.
- Surrogacy where another woman carries the baby with donated eggs fertilised by the partner’s sperm may also be an option.