Infertility and Gonadotropin-Releasing Hormone (GnRH)

Gonadotropin-Releasing Hormone agonists (GnRH) are usually part of IVF treatment. GnRH agonists initially causes a rapid increase in the production of the hormones FSH and LH. After this brief increase, your pituitary gland's hormone production stops and this prevents natural ovulation. Your fertility doctor will then artificially stimulate ovulation by using other fertility drugs and this causes production of multiple eggs (superovulation) that will be used for Assisted Reproductive Technologies.

Gonadotropin-releasing hormone antagonist blocks the GnRH receptor, resulting in an immediate drop in gonadotropin (FSH, LH) secretion. The GnRH antagonist is used in IVF treatments to prevent natural ovulation.

Using a GnRH agonist, the ovulation stops after several days, but with antagonists, ovulation stops almost immediately because it quickly blocks the effect of GnRH on the pituitary gland. Because of this, antagonists are used only for a short period.

Read more details about Gonadotropin-Releasing Hormone (GnRH).

Many clinical studies confirm the efficacy of GnRH analogues. GnRH agonists and gonadotropins combination therapy have been extensively investigated for ovarian stimulation In-Vitro Fertilization. This regimen has been shown to be effective in women who do not respond well to gonadotropin stimulation or who have premature ovulation. Major benefits of the combination therapy seem include prevention of premature ovulation, recovery of a larger number of oocytes, lowered incidence of canceled cycles, and an enhanced pregnancy rate.

In a recent study, the GnRH antagonist ganirelixin doses ranging from 0.125 mg to 2.0 mg was given for 5 days beginning on day 7 of the stimulated cycle. Investigators found out that the regimen was effective in suppressing the endogenous LH surge and preventing premature ovulation. The highest pregnancy rates were achieved when a daily dose of 0.25 mg of the ganirelixin was used.

GnRH agonists

Leuprolide acetate is injected under the skin, while depo leuprolide acetate is injected into a muscle. Leuprolide injections should be given for 10 days to stop ovulation, after which, your fertility specialist will give other medicines that will stimulate ovulation in preparation for assisted reproductive technologies

GnRH antagonists

Cetrorelix (Cetrotide ) is injected subcutaneously (just under the skin). It is available in a 3mg single-dose regimen and a 0.25mg daily dose to be given on stimulation day five or seven. Your doctor will determine which treatment regimen would benefit you best.

Ganirelix Acetate Injection 250 µg is injected subcutaneously once daily on specific days of the menstrual cycle between the use of other infertility medications such as FSH and HCG.

Side effects and cautions

When given with ovulation-stimulating treatment, GnRH analogues don't cause low-estrogen symptoms. But when taken alone, GnRH analogues may cause a temporary condition which has the same effects as menopause, such as:

• hot flashes
• mood swings
• decreased sexual interest
• vaginal dryness
• increased low-density lipoprotein (LDL) cholesterol level
• decreased high-density lipoprotein (HDL)
• cholesterol
• insomnia and
• headaches.

These side effects will go away when you stop using a GnRH agonist

GnRH antagonist therapy can cause: * nausea or * swelling, redness, or itching at the injection site.

1. Delay of gonadotropin stimulation in patients receiving gonadotropin-releasing hormone agonist (GnRH-a) therapy permits increased clinic efficiency and may enhance in vitro fertilization (IVF) pregnancy rates. Mark A. Damario M.D. Corresponding Author Contact Information, Maureen Moomjy M.D.a, Drew Tortoriello M.D.a, Fred Moy Ph.D.b, Owen K. Davis M.D.a and Zev Rosenwaks M.D.; Clinical Gynaecology T. F. Kruger, M. H. Botha

2. http://www.webmd.com/infertility-and-reproduction/gonadotropin-releasing-hormone-analogues-for-infertility