Follicle stimulating hormone

Keywords: FSH

Specimen:

5 mL blood in lithium heparin tube.

Method:

Immunoassay.

Reference Interval:

Method dependent, and related to menstrual cycle in females.

Female: 1.0-8.0 U/L

Post-menopausal female: > 18.0 U/L

Adult male: 1.0-5.0 U/L (age related).

Application:

Investigation of gonadal hypofunction, suspected pituitary tumour.

Interpretation:

Levels are increased when pituitary secretion occurs in the absence of feedback inhibition by gonadal androgens or oestrogens (primary gonadal hypofunction, post-menopausal state, castration).

Increased levels may also be seen with pituitary gonadotroph tumours, although some tumours secrete only the α subunit.

Levels are decreased if ovarian or testicular failure is due to pituitary or hypothalamic disease.

AMH is a more reliable marker of ovarian reserve.

Reference:

Thorner MO et al. In: Wilson JD and Foster DW eds. Williams Textbook of Endocrinology. 8th ed 1992. WB Saunders.