title: Blastocyst-stage embryo transfer in patients who failed to conceive in three or more day 2-3 embryo transfer cycles: a prospective, randomized study.
abstract: OBJECTIVE
  To compare blastocyst-stage embryo transfers (ETs) with day 2-3 ETs in patients who failed to conceive in three or more day 2-3 IVF/ET cycles.
  
  
  METHODS
  Prospective, randomized.
  
  
  METHODS
  Fertility unit in a university medical center.
  
  
  METHODS
  Fifty-four patients with an adequate ovarian response underwent oocyte retrievals. The patients were prospectively and randomly divided into blastocyst-stage and day 2-3 ET groups.
  
  
  METHODS
  Ovarian down-regulation was obtained using GnRH agonist, and controlled ovarian hyperstimulation was achieved using daily administration of gonadotropins.
  
  
  METHODS
  The rate of blastocyst formation, ET cancellations, pregnancies, implantation, multiple gestation, and live births.
  
  
  RESULTS
  The clinical pregnancy rates per oocyte retrieval were 21.7% and 12.9% per blastocyst and day 2-3 ETs, respectively. Although there was a significantly higher implantation rate for blastocyst embryos (21.2%) as compared with 48- to 72-hour embryos (6%), the multiple-pregnancy rate was not significantly different between both groups. An ET cancellation rate of 26% and 6.4% for blastocyst and day 2-3 ETs, respectively, was observed. The presence of two or more 8-cell embryos on day 3 in culture carried a high probability of obtaining blastocysts for transfer.
  
  
  CONCLUSIONS
  This prospective randomized study suggests that in patients with an adequate ovarian response who failed to conceive in at least three IVF/ET cycles [1]. transfer of blastocyst-stage embryos carries a significantly higher implantation rate; [2]. the pregnancy rate per oocyte retrieval and ET are higher in the blastocyst-stage group, even if it did not reach statistical significance; [3]. a higher ET cancellation rate was observed in the whole blastocyst-stage group; [4]. the ET cancellation rate was reduced significantly if the decision to proceed to blastocyst transfer was made on day 3 after oocyte retrieval, which is a post hoc conclusion.
authors.affiliation: Department of Obstetrics and Gynecology, Soroka University Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. loits@bgumail.bgu.ac.il
authors.forename: Eliahu
authors.initials: E
authors.lastname: Levitas
authors.forename: Eitan
authors.initials: E
authors.lastname: Lunenfeld
authors.forename: Iris
authors.initials: I
authors.lastname: Har-Vardi
authors.forename: Sarit
authors.initials: S
authors.lastname: Albotiano
authors.forename: Yael
authors.initials: Y
authors.lastname: Sonin
authors.forename: Rinat
authors.initials: R
authors.lastname: Hackmon-Ram
authors.forename: Gad
authors.initials: G
authors.lastname: Potashnik
mesh_terms: D001723:Birth Rate; D002452:Cell Count; D010064:Embryo Implantation; D004624:Embryo Transfer; D004622:Embryo, Mammalian / Q000166:cytology; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D011247:Pregnancy; D018873:Pregnancy Rate; D011272:Pregnancy, Multiple; D019233:Retreatment; D017211:Treatment Failure