How Do Ovulation Stimulators Work?

Ovulation stimulators are medications used to stimulate ovulation in women who have infrequent and irregular ovulation (oligo-ovulation) or absent ovulation (anovulation). Ovulation stimulators are hormonal medications that stimulate the growth, maturation, and release of healthy eggs from the ovaries (female gonads).

Natural hormones known as gonadotropins are responsible for ovulation and the conditions required for subsequent fertilization, implantation, maintenance of pregnancy, and fetal growth. Ovulation stimulators function like endogenous gonadotropins to promote ovulation.

Ovulation stimulators are gonadotropins manufactured in labs using recombinant DNA technology, or purified gonadotropins derived from the urine of pregnant or postmenopausal women. Endogenous 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. FSH and LH work in coordination to stimulate ovulation and ovarian production of the female sex hormones estrogen and progesterone essential for ovulation and implantation of the fertilized ovum.

The placenta produces hCG after implantation, which binds to LH receptors in the ovary and stimulates continued production of progesterone required for fetal growth. All three gonadotropins including hCG are used as ovulation stimulators because hCG works as a substitute for LH to stimulate ovulation.

Gonadotropins FSH and LH are also produced by the testes which play vital roles in normal growth, sexual development, and production of sperm (spermatogenesis) and testosterone in males. Hence, ovulation stimulators are also used to stimulate spermatogenesis in males and to treat the condition of undescended testicles in prepubertal boys.

Ovulation stimulators may be administered as intramuscular (IM) injections into the muscle, or subcutaneous (SC) injections into the tissue under the skin. All three ovulation stimulators FSH, LH, and hCG, and the gonadotropin-releasing hormone may be used at the appropriate phases to induce ovulation.

Ovulation stimulators 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 ovulation stimulators 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 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
  • 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 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 abdominal cavity, called 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 ovulation stimulator 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