title: Frozen-thawed cleavage-stage embryo transfer cycles after previous GnRH agonist or antagonist stimulation.
abstract: This study presents the results of fresh and frozen-thawed embryo transfers in women undergoing IVF with gonadotrophin-releasing hormone (GnRH) agonists and GnRH antagonists. By evaluating cycle outcomes, the impact of two different protocols on the endometrium was indirectly evaluated. For 714 women, embryos were frozen following day-3 fresh embryo transfer and the outcome of those fresh cycles (329 agonist cycles and 290 antagonist cycles) and subsequent frozen-thawed embryo transfer (91 agonist cycles and 104 antagonist cycles) were evaluated. Peak oestradiol concentrations of both groups were similar; however, significantly more oocytes were retrieved and more embryos frozen in the agonist versus antagonist group (both P = 0.0001). In fresh embryo transfer cycles, implantation and pregnancy rates in the agonist versus antagonist group were 42.3% versus 32.0% (P = 0.0001) and 68.6% versus 58.2% (P = 0.009) respectively. However, neither implantation or pregnancy rate significantly differed among frozen-thawed embryo transfer cycles between the two groups (21.4% versus 23.5% and 52.2% versus 52.4% respectively). These results suggest that ovarian stimulation parameter outcomes of GnRH antagonist cycles were not inferior to GnRH agonist cycles, therefore reduced embryo implantation and pregnancy rates in GnRH antagonist cycles can be attributable to possible deleterious effects on the endometrium.
authors.affiliation: Bahçeci Women Health Care Centre and German Hospital in Istanbul, Istanbul, Turkey. mbahceci@superonline.com
authors.forename: Mustafa
authors.initials: M
authors.lastname: Bahçeci
authors.forename: Ulun
authors.initials: U
authors.lastname: Ulug
authors.forename: Halit Firat
authors.initials: HF
authors.lastname: Erden
authors.forename: Suleyman
authors.initials: S
authors.lastname: Tosun
authors.forename: Nadir
authors.initials: N
authors.lastname: Ciray
mesh_terms: D000293:Adolescent; D000328:Adult; D002970:Cleavage Stage, Ovum / Q000187:drug effects / Q000502:physiology*; D010064:Embryo Implantation / Q000187:drug effects; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods; D005615:Freezing / Q000009:adverse effects; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists* / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors* / Q000627:therapeutic use; D006727:Hormone Antagonists / Q000627:therapeutic use; D006801:Humans; D010062:Ovulation Induction / Q000379:methods*; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D006727:Hormone Antagonists; D007987:Gonadotropin-Releasing Hormone; C062876:cetrorelix