IVF patients undergoing ovulation induction with FSH must not ovulate before their eggs are retrieved. Normally, the body releases a surge of LH to signal ovulation, which must not occur in an IVF cycle. Lupron and Ganirelix/Cetrotide allow the physician to precisely control the hormonal events occurring during the ovulatory cycle, including ovulation.

Lupron is given during an IVF cycle stimulation to down-regulate or suppress the pituitary gland thereby preventing an LH surge from interfering with the cycle. FSH is given by injection and the growth and maturation of the follicles is closely monitored. Lupron also essentially blocks the production of estrogen, which is why it is effective in treating endometriosis. (Endometrial tissue is dependent upon estrogen for growth and support).

Once the fertility specialist judges that the follicles are mature, an injection of human chorionic gonadotropin (hCG) is given and egg retrieval is scheduled. Eggs will not be obtained at the time of egg retrieval unless hCG is given.

Ganirelix Acetate and Cetrotide produce the same effects as Lupron albeit by different mechanisms. These products are known as GnRH antagonists and they block the production of LH and FSH by the pituitary. Ganirelix Acetate/Cetrotide act more rapidly to block FSH/LH production compared to Lupron, therefore they can be given in lower doses for shorter periods of time. Ganirelix and Cetrotide are GnRH antagonists ( blocking the effect of GnRH ) that immediately suppress luteinizing hormone ( LH ). These medications are initiated during the later part of stimulation cycle when the follicles begin to increase in size, whereas Lupron requires ten to twenty days of treatment in the previous cycle. Both antagonists and agonists can be used to eliminate a premature LH surge.

Since all of these products produce a down-regulated state (natural production of reproductive hormones is blocked), they produce side effects similar to menopause if taken for an extended time. These side effects can include hot flashes, mood swings, nausea, and many others.

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