There are many fertility drugs available for the treatment of female infertility. One class of fertility drugs is known as ovulation induction agents. Clomid is a member of this class and is discussed on a separate page. The other fertility drugs in this class are the gonadotropins and include Gonal-F, Follistim, Bravelle, Repronex and others.

Gonadotropin hormones are produced by the pituitary gland and include follicle stimulating (FSH) and luteinzing hormones (LH). The pituitary gland is influenced by gonadotropin releasing hormone (GnRH) which is excreted by the hypothalamus. The hypothalamus is part of a biofeedback mechanism know as the hypothalamic, pituitary, adrenal axis. The hypothalamus "measures" levels of various hormones, such as estrogen, and stimulates the production of FSH by the pituitary accordingly.

Pergonal was the first gonadotropin fertility drug marketed for ovulation induction and it was derived from the urine of post menopausal women. FSH levels rise dramatically after menopause and it is excreted in the urine. Pergonal is not "pure" FSH because it has equal amounts of FSH and LH.

Recent pure FSH products, such as Gonal-F and Follistim, are produced by genetic recombinant technologies and are identical to human FSH.

FSH stimulates the ovaries directly causing the recruitment and development of many eggs. They are administered by injection and directly stimulate the development of eggs within the ovarian follicles. FSH is used in virtually all ART cycles because additional eggs are needed for the manipulation processes.

FSH can cause side effects and patients must be closely monitored by a reproductive endocrinologist. Dosages are adjusted based upon each patient's individual response to avoid conditions such as ovarian hyperstimulation syndrome (See the Serono Web site for more information on this condition.)

Lupron, Antagon, Cetrotide

The hypothalamus releases gonadotropin releasing hormone (GrRH) which stimulates the pituitary to produce FSH. FSH then stimulates egg recruitment and development within the ovarian follicles. Fertility durgs in this category block the effects of GnRH albeit by different mechanisms. When GnRH is blocked the pituitary cannot produce significant amounts of FSH and LH thus follicular development and ovulation are "blocked". This condition is termed "down regulation".

IVF patients usually receive either Lupron or Antagon/Cetrotide based upon their treatment plan. Once the patient is down regulated, FSH is administered to stimulate follicular development and continued until the eggs mature. These patients cannot ovulate until an injection of hCG is given, therefore, the IVF team can precisely monitor/time the cycle.

Antagon completely blocks the effects of GnRH meaning fewer injections are necessary. However, more FSH may be required to stimulate adequate egg development.

READ ABOUT DEPOT LUPRON

Human Chorionic Gonadotropin (hCG)

The first hCG fertility drug, Profasi and Pregnyl, were derived from chorionic cells found within the placental tissue. During a normal ovulatory cycle, the pituitary releases a burst of LH, which stimulates ovulation (egg release). Most women undergoing ovulation induction are down regulated by medications such as Lupron or Antagon. These products block the pituitary's production of LH and ovulation can not occur until the drug is discontinued or an external source of LH is added.

Ovulation can be triggered by an injection of hCG because the body does not differentiate between LH and hCG. Once hCG is given the IVF retrieval, I or insemination (if it is an IUI cycle), is scheduled 36 hours later. This timing mimics the body's natural cycle.

Serono Laboratories launched Ovidrel, which is a pure hCG product and Luveris, which is pure LH. Both of these products are derived from genetic recombinant technology. Luveris allows physicians to precisely titrate the dosages of FSH and LH.