Both biochemical blood tests and ultrasound imaging of the ovaries are part of ovarian reserve tests. Basal Follicle-stimulating hormone (FSH) and estradiol, Anti-Mullerian hormone (AMH) and Antral follicle count (AFC) are widely used for the assessment of ovarian reserve.
FSH and estradiol: FSH and estradiol levels in the blood are measured at the start of the menstrual cycle (day 2 or 3). Hormone levels show the way of working of ovaries and the pituitary gland together. The pituitary gland releases FSH, which helps to grow the follicle. Usually, FSH levels are low at the start of the menstrual cycle and then increase causing a follicle to grow and the egg to mature. During this time follicle releases estradiol. Higher levels of estradiol stimulate the pituitary gland in turn to make less FSH.
A high FSH level indicates reduced ovarian reserve and therefore a reduced chance to conceive. A diagnosis of depletion of eggs or sterility will need additional more reliable tests to confirm, such as Anti-Mullerian hormone and Antral follicle count.
Anti-Mullerian hormone (AMH) is considered to be one of the most accurate tests to evaluate ovarian reserve. Elevated level of AMH is associated with increased numbers of mature oocytes, embryos and ultimately a higher clinical pregnancy rate.
Antral follicle count (AFC) refers to the number of follicles measuring 2-10 mm in diameter as assessed by transvaginal ultrasound scan. The number of antral follicles indicates the number of eggs available and the likely response to hormonal stimulation medications.