Test Background In women, FSH stimulates the growth and development of ovarian follicles during the follicular phase of the menstrual cycle. Throughout the menstrual cycle, it stimulates the aromatase enzyme in granulose cells to convert androgens to oestrogens, and its synthesis and secretion from the pituitary is controlled by negative feedback by oestradiol. FSH rises during and after the menopause when oestradiol falls due to depletion of ovarian follicles. In men, FSH stimulates the testes to produce mature sperm and circulating FSH is relatively unaltered with age.
Clinical Indications Suspected infertility (men/women) Investigations of hypopituitarism and hypogonadism Differential diagnosis of primary ovarian insufficiency and menopause