title: GnRH agonist versus GnRH antagonist in oocyte donation cycles: a prospective randomized study.
abstract: BACKGROUND
  The specific role of LH in folliculogenesis and oocyte maturation is unclear. GnRH antagonists, when administered in the late follicular phase, induce a sharp decrease in serum LH which may be detrimental for IVF outcome. This study was performed to evaluate whether the replacement of GnRH agonist (triptorelin) by a GnRH antagonist (ganirelix; NV Organon) in oocyte donation cycles has any impact on pregnancy and implantation rates.
  
  
  METHODS
  A total of 148 donor IVF cycles was randomly assigned to use either a GnRH antagonist daily administered from the 8th day of stimulation (group I) or a GnRH agonist long protocol (group II) for the ovarian stimulation of their donors. The primary endpoints were the pregnancy and the implantation rates.
  
  
  RESULTS
  The clinical pregnancy rate per transfer (39.72%, 29/73 versus 41.33%, 31/75) based on transvaginal scan findings at 7 weeks of gestation, the implantation rate (23.9 versus 25.4%) and the first trimester abortion rate (10.34 versus 12.90%) were similar in the two groups.
  
  
  CONCLUSIONS
  In oocyte donation cycles the replacement of GnRH agonist by a GnRH antagonist appears to have no impact on the pregnancy and implantation rates when its administration starts on day 8 of stimulation.
authors.affiliation: 4th Department of Obstetrics and Gynecology, Aristotle University of Thessaloniki, Greece.
authors.forename: N
authors.initials: N
authors.lastname: Prapas
authors.forename: Y
authors.initials: Y
authors.lastname: Prapas
authors.forename: Y
authors.initials: Y
authors.lastname: Panagiotidis
authors.forename: S
authors.initials: S
authors.lastname: Prapa
authors.forename: P
authors.initials: P
authors.lastname: Vanderzwalmen
authors.forename: R
authors.initials: R
authors.lastname: Schoysman
authors.forename: G
authors.initials: G
authors.lastname: Makedos
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology; D000328:Adult; D004305:Dose-Response Relationship, Drug; D010064:Embryo Implantation; D005260:Female; D005307:Fertilization in Vitro; D005640:Follicle Stimulating Hormone / Q000627:therapeutic use; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists* / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors* / Q000627:therapeutic use; D006727:Hormone Antagonists / Q000627:therapeutic use; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D018587:Oocyte Donation / Q000379:methods*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011446:Prospective Studies; D017329:Triptorelin Pamoate / Q000627:therapeutic use*
chemical_list: D006727:Hormone Antagonists; D017329:Triptorelin Pamoate; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; C061018:ganirelix