title: Transfer at the blastocyst stage of embryos derived from testicular round spermatid injection.
abstract: BACKGROUND
  Intracytoplasmic injection of testicular round spermatids has been suggested as a salvage treatment in couples when testicular sperm extraction does not yield any mature sperm. However, the success of the procedure is debatable, and controversy surrounds issues such as the presence and (if present) identification of spermatids in testicular tissue. Progression rate to the blastocyst stage of spermatid-derived embryos appears to be low.
  
  
  METHODS
  In this study, we investigated the feasibility and outcome of blastocyst stage embryo transfer after round spermatid injection (ROSI). ROSI was undertaken in 58 couples who did not yield mature or elongated sperm to testicular sperm extraction.
  
  
  RESULTS
  The incidence of blastocyst formation from two pronuclear oocytes was 7.6%. A total of 16 blastocysts were transferred in 12 patients (20.7%). None of the patients conceived.
  
  
  CONCLUSIONS
  The results of this study indicate that the blastocyst stage is reached by only very few ROSI-derived embryos and these embryos do not implant.
authors.affiliation: The Assisted Reproduction Unit, American Hospital of Istanbul, Guzelbahce sok. No:20, Nisantasi 80200, Istanbul, Turkey. burman@superonline.com
authors.forename: Bulent
authors.initials: B
authors.lastname: Urman
authors.forename: Cengiz
authors.initials: C
authors.lastname: Alatas
authors.forename: Senai
authors.initials: S
authors.lastname: Aksoy
authors.forename: Ramazan
authors.initials: R
authors.lastname: Mercan
authors.forename: Alp
authors.initials: A
authors.lastname: Nuhoglu
authors.forename: Alper
authors.initials: A
authors.lastname: Mumcu
authors.forename: Aycan
authors.initials: A
authors.lastname: Isiklar
authors.forename: Basak
authors.initials: B
authors.lastname: Balaban
mesh_terms: D048429:Cell Size; D004624:Embryo Transfer; D005260:Female; D005306:Fertilization; D006801:Humans; D008297:Male; D020554:Sperm Injections, Intracytoplasmic; D013087:Spermatids / Q000502:physiology*; D013737:Testis / Q000166:cytology*; D017211:Treatment Failure