FSH

Follicle Stimulating Hormone Test

This test measures the level of Follicle Stimulating Hormone in the body. It is prescribed to evaluate infertility, pituitary function or altered sexual maturation in children.

FSH is a glycoprotein hormone produced and stored in the anterior pituitary together with LH. It stimulates steroidogenesis and gametogenesis in the gonads. FSH regulates the menstrual cycle and ovarian follicular maturation in women and supports sperm production in men. FSH acts by binding to the FSH receptor on the granulosa cell surface in ovaries and the sertoli cell surface in testes. 

Measurement of serum FSH is useful in the work up of patients with delayed or precocious puberty, infertility, and pituitary disorders. FSH levels are measured in infertility to distinguish primary failure of the ovary or testis from pituitary hypofunction. 

FSH levels are elevated in men with primary testicular failure, castration, and Klinefelter's syndrome. FSH levels are elevated in women with menopause, ovariectomy, ovarian agenesis, and Turner's syndrome.

FSH levels are decreased in men with hypogonadism, hypopituitarism, hypothalamic suppression, adrenal tumors, and testosterone medications. In women, decreased FSH levels are seen in hypopituitarism, hypothalamic suppression, adrenal or ovarian tumors, polycystic ovaries, menstrual disorders, oral contraceptives, and estrogen therapy.In Pretesticular azoospermia or oligozoospermia, low FSH levels (hypogonadotropic) commensurate with inadequate stimulation of the testes to produce sperm. In testicular azoospermia or oligozoospermia, elevated FSH levels (hypergonadotropic) via testicular failure leads to failure production as well as low production and maturation arrest during the process of spermatogenesis. This condition is seen in 50-90% of men with azoospermia.