GnRH Antagonists
About GnRH
GnRH is a hormone the hypothalamus gland produces in the brain that controls the pituitary gland's production and release of luteinizing hormone (LH) and follicle stimulating hormone (FSH). The amount of GnRH released from the hypothalamus gland fluctuates throughout a woman's menstrual cycle. Halfway through each cycle, a large amount of GnRH is released. This increase in GnRH increases the production and release of LH, as well as the production and release of LH. This surge is responsible for initiating ovulation.
When used as part of an infertility treatment regimen, such as IVF, these medications block the effect of GnRH on the pituitary gland. Therefore, the LH surge and natural ovulation are prevented. This allows the timing of ovulation to be better predicted and coordinated with procedures such as egg retrieval.
Back to top
Side Affects
Side effects reported during treatment with these medications include abdominal pain (gynecological and gastrointestinal), nausea, headache, vaginal bleeding, and injection site reactions (redness or swelling at or near the site of injection). Another reported side effect was ovarian hyperstimulation syndrome (OHHS), a condition characterized by enlargement of the ovaries due to overstimulation by fertility medications. Symptoms of OHSS include abdominal pain and/or swelling, pelvic pain, nausea, vomiting, diarrhea and weight gain. These medications are administered subcutaneously once daily during the mid to late follicular phase.
Back to top
