title: GnRH agonist versus GnRH antagonist in ovarian stimulation: is the emperor naked?
abstract: OBJECTIVE
  The aim of the study was to evaluate the influence of type of GnRH-analog used during controlled ovarian hyperstimulation (COH) on the outcome of in vitro fertilization (IVF) cycles.
  
  
  METHODS
  All consecutive women aged < or = 35 years admitted to our IVF unit from January 2001 to December 2004 were enrolled in the study. Only patients undergoing up to their third IVF cycle attempt were included. Ovarian stimulation characteristics, number of oocytes retrieved, number of embryos transferred, and clinical pregnancy rate were compared between women given GnRH-agonist or GnRH-antagonist during COH.
  
  
  RESULTS
  Four hundred and eighty-seven consecutive IVF cycles were evaluated, 226 in the agonist group and 261 in the antagonist group. A clinical pregnancy was achieved in 93 patients in the agonist group (pregnancy rate 41.2% per cycle) and 66 patients in the antagonist grup (pregnancy rate 25.3%); this difference was statistically significant (p < 0.01). The agonist group also used significantly more gonadotropin ampoules, required longer stimulation, and had higher estradiol levels on the day of human chorionic gonadotropin administration.
  
  
  CONCLUSIONS
  The midluteal long GhRH-agonist suppressive protocol should be the protocol of choice in young patients in their first three IVF cycle attempts.
authors.affiliation: Department of Obstetrics and Gynecology, Barzilai Medical Center, Ashkelon, Isarel.
authors.forename: R
authors.initials: R
authors.lastname: Orvieto
authors.forename: J
authors.initials: J
authors.lastname: Rabinson
authors.forename: S
authors.initials: S
authors.lastname: Meltzer
authors.forename: R
authors.initials: R
authors.lastname: Homburg
authors.forename: E
authors.initials: E
authors.lastname: Anteby
authors.forename: E
authors.initials: E
authors.lastname: Zohav
mesh_terms: D000328:Adult; D005260:Female; D005307:Fertilization in Vitro / Q000187:drug effects*; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists* / Q000037:antagonists & inhibitors*; D006801:Humans; D010062:Ovulation Induction / Q000379:methods*; D011247:Pregnancy; D018873:Pregnancy Rate
chemical_list: D007987:Gonadotropin-Releasing Hormone