Substituting HCG with GnRH agonist to trigger final follicular maturation – a retrospective comparison of three different ovarian stimulation protocols

• Published in: Reproductive biomedicine online 2006-08, Vol.13 (2), p.198-201
• Main Authors: Orvieto, Raoul, Rabinson, Jacob, Meltzer, Simion, Zohav, Efraim, Anteby, Eyal, Homburg, Roy
• Format: Article
• Language: English
• Subjects: Adult; Chorionic Gonadotropin - therapeutic use; Embryo Implantation - drug effects; Female; Fertility Agents, Female - therapeutic use; GnRH agonist; GnRH antagonist; Gonadotropin-Releasing Hormone - agonists; Gonadotropin-Releasing Hormone - antagonists & inhibitors; Humans; Infertility, Female - drug therapy; IVF outcome; Oocytes - drug effects; Oocytes - growth & development; Ovarian Follicle - drug effects; Ovarian Follicle - growth & development; Ovarian Hyperstimulation Syndrome - complications; Ovulation Induction - adverse effects; Ovulation Induction - methods; Pregnancy; Pregnancy Rate; Retrospective Studies
• ISSN: 1472-6483; 1472-6491
• DOI: 10.1016/S1472-6483(10)60615-3

The study retrospectively evaluated the influence of triggering final oocyte maturation with gonadotrophin-releasing hormone (GnRH) agonist on the outcome of IVF cycles. Four hundred and sixty consecutive women admitted to the IVF unit during a 4-year period were enrolled in the study. Ovarian stimulation characteristics and clinical pregnancy rate were compared between three groups: patients at risk of developing ovarian hyperstimulation syndrome (OHSS), undergoing either the long GnRH-agonist protocol (agonist group) or the flexible multidose GnRH-antagonist protocol who received GnRH-agonist for final oocyte maturation (antagonist–agonist group); and patients not at risk of developing severe OHSS undergoing the flexible multidose GnRH-antagonist protocol who received human chorionic gonadotrophin (HCG) for final oocyte maturation (antagonist-HCG group). Implantation and clinical pregnancy rates were lowest in the antagonist–agonist group despite the fact that no difference were was observed in fertilization rates between the groups. Moreover, the high-responder antagonist–agonist group required shorter stimulation and had higher numbers of oocytes retrieved as compared with the high-responder agonist-group. No case of severe OHSS was observed in the antagonist–agonist group. The use of flexible multidose GnRH-antagonist protocol with GnRH-agonist for final oocyte maturation, in high-responder patients, eliminates the risk of OHSS but results in decreased implantation and pregnancy rates.