Follicle Stimulating Hormone

Abbreviated as FSH. A hormone secreted by the pituitary gland; FSH stimulates the growth and development of ovarian follicles. It is the main hormone present in the gonadatropin medications Gonal-F, Follistim and Bravelle, and comprises half of the hormones in Menopur. A blood test for this hormone on the third day of the menstrual cycle is crucial in evaluating how the ovaries are functioning. A significantly elevated level (>10) implies possible decreased ovarian reserve.

Women with higher basal FSH levels may not respond as well to fertility medications in terms of the numbers of follicles and eggs recruited but does not necessarily predict who will and who will not get pregnant. Age is a better predictor of successful pregnancy. The level of FSH also assists us in determining the ideal dosage and regimen of fertility agents necessary to initiate proper ovarian stimulation in a subsequent cycle of treatment.