title: A novel approach using a minimal number of injections during the IVF/ICSI cycle: Luteal half-dose depot GnRH agonist following corifollitropin alfa versus the corifollitropin alfa with a GnRH-antagonist cycle.
abstract: OBJECTIVE
  Corifollitropin alfa is a good choice for assisted reproductive technology (ART) cycles because fewer injections are needed than with other agents. In this retrospective cohort, we analyzed luteal injected half-dose depot gonadotropin hormone-releasing hormone (GnRH) agonist cycles in women who received corifollitropin alfa and those who underwent a conventional corifollitropin alfa cycle with a GnRH antagonist.
  
  
  METHODS
  In this retrospective cohort, we analyzed luteal injected half-dose depot GnRH agonist cycles in women who received corifollitropin alfa and those who underwent a conventional corifollitropin alfa cycle with a GnRH antagonist at the Division of Reproductive Endocrinology and IVF Unit, Obstetrics and Gynecology Department, Başkent University School of Medicine, Adana, Turkey, from March 2014 to August 2015. The patient's baseline characteristics were similar between the two groups. Forty-five patients underwent the long protocol, in which a half-dose of depot GnRH agonist was administered on day 21 of the preceding cycle. Forty-nine patients underwent the GnRH-antagonist protocol. Corifollitropin alfa was administered on the menstrual cycle day 3.
  
  
  RESULTS
  The mean ages of the two groups were similar (32.77±5.55 vs. 34.2±4.51 years ["for the long- and antagonist-protocol groups, respectively"]). The total number of retrieved oocytes, the fertilization rate, and the number of transferred embryos were similar between the two groups. The only significant difference between the two protocols was the number of injections during the controlled ovarian stimulation (COH) cycle, which included the depot-agonist injection in the long-protocol group (4.46±1.64 vs. 5.71±2.51, p=0.006). The clinical pregnancy and implantation rates were similar in the two protocols (16/45 [35.6%] vs. 16/49 [32.7%] for the intention to treat and 32.5±6.82% vs. 36.25±8.58%, respectively).
  
  
  CONCLUSIONS
  Our results show that ART cycles could be performed with fewer injections using corifollitropin alfa and a half-dose of depot GnRH agonist.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and IVF Unit, Başkent University School of Medicine Adana, Turkey.
authors.forename: Bülent
authors.initials: B
authors.lastname: Haydardedeoğlu
authors.affiliation: Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and IVF Unit, Başkent University School of Medicine Adana, Turkey.
authors.forename: Esra Bulgan
authors.initials: EB
authors.lastname: Kılıçdağ
keywords: Corifollitropin alfa; GnRH antagonist; IVF/ICSI outcomes; depot GnRH agonist