Follicle-Stimulating Hormone

Synonym/Acronym

Follitropin, FSH.

Rationale

To distinguish primary causes of gonadal failure from secondary causes, evaluate menstrual disturbances, and assist in infertility evaluations.

Patient Preparation

There are no food, fluid, activity, or medication restrictions unless by medical direction.

Normal Findings

Method: Electrochemiluminescence Immunoassay.

Age		Conventional Units and SI Units
Child
Prepuberty		Less than 10 international units/L
Adult
Male		1.4–15.5 international units/L
Female
Follicular phase		3.5–12.5 international units/L
Ovulatory peak		4.7–21.5 international units/L
Luteal phase		1.7–7.7 international units/L
Postmenopause		25.8–134.8 international units/L

Critical Findings and Potential Interventions ⬆ ⬇

Overview ⬆ ⬇

Study type: Blood collected in a gold-, red-, or red/gray-top tube; related body system: Endocrine and Reproductive systems.

Follicle-stimulating hormone (FSH) is produced and stored in the anterior portion of the pituitary gland. In women, FSH promotes maturation of the graafian (germinal) follicle, causing estrogen secretion and allowing the ovum to mature. In men, FSH partially controls spermatogenesis, but the presence of testosterone is also necessary. Gonadotropin-releasing hormone secretion is stimulated by a decrease in estrogen and testosterone levels. Gonadotropin-releasing hormone secretion stimulates FSH secretion. FSH production is inhibited by an increase in estrogen and testosterone levels. FSH production is pulsatile, episodic, and cyclic and is subject to diurnal variation. Serial measurement is often required.

Indications ⬆ ⬇

Assist in distinguishing between primary and secondary (pituitary or hypothalamic) gonadal failure.
Define menstrual cycle phases as a part of infertility testing.
Evaluate ambiguous sexual differentiation in infants.
Evaluate early sexual development in girls younger than age 9 or boys younger than age 10 (precocious puberty associated with elevated levels).
Evaluate failure of sexual maturation in adolescence.
Evaluate testicular dysfunction.
Investigate impotence, gynecomastia, and menstrual disturbances.

Interfering Factors ⬆ ⬇

Factors That May Alter the Results of the Study

Drugs and other substances that may increase FSH levels include bicalutamide, bombesin, cimetidine, clomiphene, digoxin, erythropoietin, exemestane, finasteride, gonadotropin-releasing hormone, ketoconazole, levodopa, metformin, nafarelin, naloxone, nilutamide, oxcarbazepine, pravastatin, and tamoxifen.
Drugs and other substances that may decrease FSH levels include anabolic steroids, anticonvulsants, buserelin, estrogens, corticotropin-releasing hormone, danazol, diethylstilbestrol, goserelin, megestrol, mestranol, oral contraceptives, phenothiazine, pravastatin, progesterone, tamoxifen, toremifene, and valproic acid.

Other Considerations

In women who are menstruating, values vary in relation to the phase of the menstrual cycle. Values are higher in women who are postmenopausal.

Potential Medical Diagnosis: Clinical Significance of Results ⬆ ⬇

Increased In

Castration (oversecretion related to feedback mechanism involving decreased testosterone levels)
Gonadal failure (oversecretion related to feedback mechanism involving decreased estrogen or testosterone levels)
Gonadotropin-secreting pituitary tumors(related to oversecretion by tumor cells)
Klinefelter syndrome(oversecretion related to feedback mechanism involving decreased estrogen or testosterone levels)
Menopause(oversecretion related to feedback mechanism involving decreased estrogen levels)
Orchitis(oversecretion related to feedback mechanism involving decreased testosterone levels)
Precocious puberty in children(related to oversecretion from the pituitary gland)
Primary hypogonadism(oversecretion related to feedback mechanism involving decreased estrogen or testosterone levels; failure of testes or ovaries to produce sex hormones)
Reifenstein syndrome (oversecretion related to feedback mechanism involving familial partial resistance to testosterone levels)
Turner syndrome(oversecretion related to feedback mechanism involving decreased estrogen or testosterone levels)

Decreased In

Anorexia nervosa(related to suppressive effects of severe caloric restriction on the hypothalamic-pituitary axis)
Anterior pituitary hypofunction(underproduction resulting from dysfunctional pituitary gland)
Hemochromatosis(hypogonadotropic hypogonadism related to absence of the gonadal-stimulating pituitary hormones, estrogen, and testosterone; iron deposits in pituitary may affect normal production of FSH)
Hyperprolactinemia(related to suppressive effect on estrogen production)
Hypothalamic disorders(decreased production in response to lack of hypothalamic stimulators)
Polycystic ovary disease (Stein-Leventhal syndrome) (suppressed secretion related to feedback mechanism involving increased estrogen levels)
Pregnancy (related to elevated estrogen levels)
Sickle cell anemia(although primary testicular dysfunction is mainly associated with sickle cell disease, related to testicular microinfarcts, hypogonadotropic hypogonadism has been reported in some men with sickle cell disease)

Nursing Implications, Nursing Process, Clinical Judgement ⬆

Before the Study: Planning and Implementation

Teaching the Patient What to Expect

Discuss how this test can assist in evaluating disturbances in hormone levels.
Explain that a blood sample is needed for the test.
Inform the patient that multiple specimens may be required.

Potential Nursing Actions

Obtain information regarding the patient’s phase of menstrual cycle.
Be attentive to verbalized concerns associated with inability to have children.
Provide family counseling references.

After the Study: Implementation & Evaluation Potential Nursing Actions

Treatment Considerations

Explain that FSH controls the menstrual cycle and egg growth in women and sperm production in men.
Note that symptoms of low FSH level include decreased sex drive, irregular or absent menstrual cycle for women, inability to impregnate for men, weight loss, fatigue, weakness, and decreased appetite.
Note that therapeutic treatment may include hormone therapy.

Clinical Judgement

Consider how to lessen the emotional impact of fertility issues. Family or individual counseling may be appropriate.

Follow-Up and Desired Outcomes

Female patients acknowledge teaching regarding the potential effects of FSH deficiency, which may include an absence of menstrual cycles, infertility, decreased sex drive, and vaginal dryness.
Male patients acknowledge teaching regarding the potential effects of FSH deficiency, which may include decreased sex drive, erectile dysfunction, and infertility.
Acknowledges information regarding the potential for development of osteoporosis with a resulting tendency to develop bone fractures, which can occur in both female and male patients with this hormone deficiency.