title: GnRH-agonist versus GnRH-antagonist IVF cycles: is the reproductive outcome affected by the incidence of progesterone elevation on the day of HCG triggering? A randomized prospective study.
abstract: BACKGROUND
  In view of the current debate concerning possible differences in efficacy between the two GnRH analogues used in IVF stimulated cycles, the current study aimed to explore whether progesterone control in the late follicular phase differs when GnRH antagonist is used as compared with GnRH agonist, and if so, to what extent the progesterone rise affects the probability of pregnancy.
  
  
  METHODS
  Overall 190 patients were randomized: 94 in the GnRH-agonist group and 96 in the GnRH-antagonist group. The GnRH-agonist long protocol started on Day 21 of the preceding cycle with intranasal buserelin (600 mg per day). The GnRH-antagonist protocol started on Day 6 of the stimulation with ganirelix or cetrorelix (each 0.25 mg). All blood samples were analysed with the Elecsys analyzer. An intention-to-treat analysis was applied.
  
  
  RESULTS
  A progesterone rise >1.5 ng/ml was noticed in 23.0% of the antagonist group, comparable with 24.1% incidence within the agonist group. Per patient randomized, delivery rates were also comparable: 28.1% in the antagonist group and 24.5% in the agonist group (odds ratio = 1.21, 95% confidence interval: 0.63-2.31, P= 0.56). However, there was a reduction in delivery rates when progesterone exceeded the threshold of 1.5 ng/ml, both in the agonist group (9.5 versus 31.8%, P= 0.03) and in the antagonist group (14.3 versus 34.3%, P= 0.07).
  
  
  CONCLUSIONS
  Although the incidence of a progesterone rise was similar between the two analogues, our findings reconfirm previous observations that insufficient progesterone control (>1.5 ng/ml) on the day of ovulation triggering is related to poor delivery rates in both protocols. The current study has shown that the reproductive outcomes with the two GnRH analogues are comparable. Possible modes of action to circumvent late follicular progesterone rise should be explored.
  
  
  BACKGROUND
  NCT01191710.
authors.affiliation: Assisted Reproduction Unit, Biogenesis, Thessaloniki, Greece. drvagpapanikolaou@yahoo.gr
authors.forename: E G
authors.initials: EG
authors.lastname: Papanikolaou
authors.forename: G
authors.initials: G
authors.lastname: Pados
authors.forename: G
authors.initials: G
authors.lastname: Grimbizis
authors.forename: E
authors.initials: E
authors.lastname: Bili
authors.forename: L
authors.initials: L
authors.lastname: Kyriazi
authors.forename: N P
authors.initials: NP
authors.lastname: Polyzos
authors.forename: P
authors.initials: P
authors.lastname: Humaidan
authors.forename: H
authors.initials: H
authors.lastname: Tournaye
authors.forename: B
authors.initials: B
authors.lastname: Tarlatzis
mesh_terms: D000328:Adult; D002064:Buserelin / Q000008:administration & dosage; D006063:Chorionic Gonadotropin / Q000008:administration & dosage*; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage / Q000819:agonists* / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors*; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome; D011374:Progesterone / Q000097:blood*; D011446:Prospective Studies; D020554:Sperm Injections, Intracytoplasmic
chemical_list: D006063:Chorionic Gonadotropin; D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; C061018:ganirelix; C062876:cetrorelix; D002064:Buserelin