When a woman is born, her ovaries contain a lifetime supply of eggs. Each month, follicle stimulating hormone (FSH) stimulates a group of eggs to mature within the ovary. In response, the ovarian follicle produces estrogen, the principal sex hormone that regulates female reproductive organs. Some women with ovarian factor infertility experience a decline in egg quantity and quality long before they hit menopause, making it difficult for them to conceive.
Failed or irregular ovarian function can be due to a variety of causes such as hormonal imbalances, environmental factors, conditions such as PCOS and hyperprolactinemia and stress. Treatments, such as radiation and chemotherapy, can also destroy ovarian tissue. In rare cases, a woman may be born without functioning ovaries or have a genetic disorder that predisposes her to premature ovarian failure.
Your egg number (ovarian reserve) can be assessed using three tests:
- Follicle Stimulating Hormone (FSH) should be measured on day 3 of your menstrual cycle. If the FSH is high (above 8 to 10 IU/L) it can be a sign that you have a lower egg number.
- The most accurate blood test for ovarian reserve is called Anti-Mullerian Hormone (AMH). AMH can be done on any day of the menstrual cycle and it is valid even on the birth control pill or when women have irregular periods. AMH is a hormone that is made directly by cells connected to the eggs, so a higher AMH indicates a higher egg number. When interpreting your AMH result keep in mind that Canada uses the units of pmol/L and the USA uses ng/ml. A ‘normal’ AMH value depends highly on your age, so a fertility doctor should help you understand your result. Patients in BC will be charged 70$ for this test directly by the laboratory (e.g. Lifelabs).
- Antral Follicle Count (AFC) is a specialized ultrasound test performed by a fertility doctor. A follicle is the small fluid-filled sac that an egg lives in. During an internal ultrasound at our clinic, your doctor will count the number of follicles on each ovary to estimate the number of eggs you have available that month. This number can go up and down each month, but it does provide a reasonable idea of how many eggs you have remaining.