Precycle administration of GnRH antagonist and microdose HCG decrease clinical pregnancy rates without affecting embryo quality and blastulation

Orhan Bukulmez, Khurram S. Rehman, Martin Langley, Bruce R. Carr, Anna C. Nackley, Kathleen M. Doody, Kevin J. Doody

Research output: Contribution to journalArticle

10 Scopus citations


The outcome of a novel protocol utilizing precycle gonadotrophin-releasing hormone (GnRH) antagonist administration and LH activity support with microdose recombinant human chorionic gonadotrophin (HCG) was compared to GnRH agonist long protocol used in patients undergoing their first ICSI (n = 707) or IVF (n = 571) cycles, which had resulted in one or two blastocyst transfers. In GnRH antagonist cycles, cetrorelix acetate (3 mg) was administered s.c. 4 days before FSH stimulation and a repeat dose was given when the lead follicular diameter was 13-14 mm. LH support was provided by recombinant HCG (2.5 μg). Embryo progression and blastulation were evaluated using embryo progression indices and blastocyst quality scores. The tested protocol demonstrated reduced implantation and clinical pregnancy rates as compared with GnRH agonist long protocol, although the embryo progression and blastulation parameters and blastocyst quality were comparable among the groups. Logistic regression models further supported the significant negative impact of GnRH antagonist/microdose HCG protocol on clinical pregnancy rates in both ICSI and IVF patients. Assisted reproduction cycles with fresh blastocyst transfers utilizing precycle GnRH antagonist administration and microdose HCG support resulted in lower implantation and clinical pregnancy rates as compared with GnRH agonist cycles, although the embryo progression and blastulation parameters were comparable.

Original languageEnglish (US)
Article number2396
Pages (from-to)465-475
Number of pages11
JournalReproductive BioMedicine Online
Issue number4
Publication statusPublished - Oct 2006



  • Assisted reproduction
  • Clinical pregnancy
  • GnRH agonist
  • GnRH antagonist
  • Implantation
  • Microdose HCG

ASJC Scopus subject areas

  • Obstetrics and Gynecology

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