[GnRH antagonists in IVF]

New GnRH antagonists are available in clinical practice. The different studies have confirmed the efficacy of these antagonists in preventing the LH surge. Two protocols have been described: in the multiple dose regimens, small doses of antagonist (0.25 mg) are injected starting on stimulation day 5 or 6 until hCG. In the single dose protocol, one injection of a larger dose (3 mg) is proposed in the late follicular phase. Local and general tolerance of the two compounds is very good. The results obtained with both regimens as compared with GnRH agonists in long protocols are showing a reduction in the stimulation length, in the consumption of gonadotrophins and in the incidence of the OHSS. The pregnancy rates are comparable in the good prognosis patients selected in the published studies. When the final tuning of these new protocols will be done, the advantages of GnRH antagonists in reducing the complications and side effects of ovarian stimulation will give to GnRH antagonists an important place in IVF.