How Do Gonadotropins Work?

Gonadotropins are a class of medications used to treat infertility and disorders associated with reproductive functions such as ovulation and the production of sperm (spermatogenesis). Gonadotropin medications function like endogenous gonadotropins which are vital for normal growth, sexual development, and reproduction.

Gonadotropins are peptide hormones that regulate the function of the reproductive organs (gonads), ovaries in females, and testes in males. Human gonadotropins include:

• Follicle-stimulating hormone (FSH)
• Luteinizing hormone (LH)
• Human chorionic gonadotropin (hCG)

The pituitary gland produces FSH and LH when stimulated by gonadotropin-releasing hormone (GnRH), which is secreted by the hypothalamus. After the implantation of the fertilized egg, the placenta produces hCG, which works like LH to promote the production of progesterone, for maintenance of pregnancy and fetal growth.

In women, the two hormones FSH and LH regulate menstruation, follicle maturation, ovulation, ovarian production of female hormones estrogen and progesterone, and preparation of the endometrium for implantation. In men, FSH and LH regulate sexual maturation, spermatogenesis, and production of the male hormone testosterone by the testes.

Improper functioning of gonadotropins can upset the fine hormonal balance that is required for reproductive health and can lead to fertility problems in both men and women. Abnormality in the hypothalamic-pituitary-gonadal axis can cause cryptorchidism in boys, a condition in which the testicle doesn’t descend into its proper place in the scrotum.

Gonadotropin medications work as substitutes for endogenous gonadotropins FSH, LH, and hCG in people who have reproductive problems. Gonadotropins used as medications are lab-manufactured products, using recombinant DNA technology, or purified extracts derived from the urine of pregnant or postmenopausal women.

Gonadotropins may be administered as intramuscular (IM) injections into the muscle, or subcutaneous (SC) injections into the tissue under the skin. All three gonadotropins FSH, LH, and hCG, and the gonadotropin-releasing hormone may be used at the appropriate phases to promote ovulation, implantation, and maintenance of pregnancy.

Gonadotropins are approved by FDA in the treatment of the following:

• Induction of ovulation and pregnancy in infertile women whose anovulation (absence of ovulation) is not due to primary ovarian failure
• Induction of ovulation and pregnancy in women with oligo-anovulation (infrequent and irregular ovulation) that is not due to primary ovarian failure
• Induction of spermatogenesis in men with hypogonadotropic hypogonadism (impaired gonad functioning due to pituitary deficiency) in whom infertility is not due to primary testicular failure
• Prepubertal cryptorchidism is not caused by anatomical obstruction
• Development of multiple follicles in women as part of assistive reproductive technologies (ART) such as in-vitro fertilization or embryo transfer 

Side effects of gonadotropins may include the following:

• Headache
• Abdominal pain and discomfort
• Nausea
• Vomiting
• Abdominal cramps
• Abdominal distention or fullness
• Diarrhea
• Constipation
• Flatulence
• Ovarian hyperstimulation syndrome
• Miscarriage
• Ovarian cyst, rupture, and pain
• Ovarian disease and enlargement
• Adnexal torsion (twisting of the ovary, a complication of ovarian enlargement)
• Vaginal spotting or bleeding
• Vaginal discharge
• Vaginitis (inflammation of the vagina)
• Menstrual irregularities
• Uterine spasms
• Cervical lesion
• Intermenstrual bleeding
• Pain after egg retrieval
• Pregnancy-related events after ART, such as:
  • Ectopic pregnancy
  • Spontaneous abortion
  • Premature labor
  • Postpartum fever
  • Multiple pregnancies
  • Congenital abnormalities
• Injection site reactions such as inflammation and pain
• Breast tenderness or pain
• Gynecomastia (breast tissue enlargement in males)
• Precocious puberty
• Emotional lability (mood swings)
• Depression
• Irritability
• Restlessness
• Edema
• Hot flashes
• Increased cough
• Asthma exacerbation
• Sinusitis (inflammation of the sinuses)
• Dizziness
• Malaise
• Fatigue
• Migraine
• Back pain
• Flu-like symptoms
• Febrile (feverish) reactions
• Toothache
• Hypersensitive reactions such as:
  • Acne
  • Rash
  • Dry skin
  • Hives
  • Erythema (redness)
  • Pruritus (itching)
  • Anaphylaxis (severe allergic reaction)
• Hair loss
• Dermoid cyst (cyst present at birth that contains skin-related tissue, such as hair, fluid, teeth, or skin glands)
• Cardiac arrhythmia (irregular heart rhythm)
• Tachycardia (rapid heartbeat)
• Dyspnea (shortness of breath)
• Tachypnea (rapid shallow breathing)
• Atelectasis (complete or partial collapse of a lung or a lobe of the lung)
• Albuminuria (high level of albumin in the urine)
• Urinary tract infection
• Hyperglycemia (high blood glucose levels)
• Arterial thrombus ((blood clot)
• Arterial thromboembolism (blockage of an artery by a blood clot)
• Hemoperitoneum (blood in the abdominal cavity within the space between the abdominal organs and the inner lining of the abdomen, called the peritoneum)
• Weight gain

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with travel medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of gonadotropin drugs include:

• Bravelle
• choriogonadotropin alfa
• chorionic gonadotropin
• Fertinorm HP
• Follistim AQ
• follitropin alfa
• follitropin beta
• Gonal-f
• Gonal-f RFF
• Menopur
• menotropins
• Novarel
• Ovidrel
• Pregnyl
• Repronex
• urofollitropin