The term ovarian reserve describes a woman’s reproductive potential with respect to the number of ovarian follicles and egg quality. A blood test measurement of the levels of FSH and estradiol on day 2 or 3 of the menstrual cycle is often used to test for ovarian reserve. Elevations in FSH or estradiol may indicate decreased ovarian reserve and may predict a poorer prognosis in women of older reproductive age. More recent ovarian reserve tests are being evaluated for clinical use including ultrasound evaluation of the number of visible follicles (antral follicle count) and measurement of a substance called anti-Mullerian hormone (AMH).