This is a blood test that measures the amount of follicle-stimulating hormone (FSH) produced by the pituitary gland.
Fertility in men and women, as well as menstruation in women, are regulated by a complex interaction of hormones. The ovaries, pituitary gland, and hypothalamus produce these hormones. Follicle-stimulating hormone, or FSH, causes the follicles within the ovaries to mature.
FSH levels may be measured if the healthcare provider suspects a problem with: menopause, a time in life when menstruation stopsovarian cysts, which are fluid-filled sacs on the ovaryprecocious puberty, or puberty that happens at an abnormally young agedelayed puberty, or puberty that hasn't occurred by the time it shouldfemale infertility, or inability to become pregnantmale infertility, or the inability to impregnate a womananovulatory bleeding, which is abnormal vaginal bleeding not related to a regular menstruation cycleamenorrhea, or the absence of menstruationtestes that are absent or abnormally small
A blood sample is taken from a vein on the forearm or hand. First, the skin over the vein is cleaned with an antiseptic. Next, a strong rubber tube, or "tourniquet," is wrapped around the upper arm. This enlarges the veins in the lower arm by restricting blood flow through them. A fine needle is gently inserted into a vein, and the tourniquet is removed. Blood flows from the vein through the needle, and is collected in a syringe or vial. After the needle is withdrawn, the puncture site is covered for a short time to prevent bleeding. The blood sample is sent to the laboratory to determine the amount of FSH circulating in the blood.
There is generally no preparation for this test. However, the healthcare provider may want to have the test done during a particular time of a woman's menstrual cycle.
Normal values depend upon the sex of the person and other factors. Greater than normal levels of FSH may be found in the following conditions: polycystic ovary disease (PCOD) or syndrome (PCOS), conditions that cause ovarian cysts and menstrual cycle problems or irregularitiesmenopausepremature ovarian failure, which may be genetic or related to radiation exposureKlinefelter syndrome, a genetic disorder that causes testicular failureTurner syndrome, a genetic disorder in which the ovaries fail to respond to pituitary hormonesabsence of the testes or their failure to produce the male hormone testosteroneprecocious puberty
Lower than normal levels may be seen with: a poorly functioning hypothalamus or pituitary glandsome cases of infertilityanorexia nervosa, an eating disorderexercise-induced amenorrhea, a condition in which a woman stops menstruating after she over-exercisesbulimia nervosa, an eating disorder with overeating followed by induced vomitinguse of oral contraceptive pills or other medicationsbreastfeeding