Unlike men who continually renew their sperm, women are born with a predefined number of eggs. A woman’s ovarian reserve gradually diminishes as she ages, and by the time she’s 35, she only has 12% of her ovarian reserve left, and 3% by the age of 40. A diminished ovarian reserve is the main cause of female age-related infertility.
Two methods are available to estimate a patient’s ovarian reserve: ultrasound and a blood test.
- Transvaginal ultrasound is a test performed in the early part of the cycle and used to count the number of antral follicles measuring 2 to 10 mm. These follicles are programmed two or three months in advance to ensure future ovulations. Given its proximity, the transvaginal probe is used to get a clearer image of the ovaries and follicles than a prob placed on the patient’s abdomen.
- Anti-Mullerian hormone (AMH) levels are an excellent indicator of ovarian reserve. The fewer the eggs, the lower the AMH levels. A blood test will measure AMH levels.