title: Developmental potential of fully intact and partially damaged cryopreserved embryos after laser-assisted removal of necrotic blastomeres and post-thaw culture selection.
abstract: OBJECTIVE
  Partially damaged frozen and thawed embryos are currently considered to have a lower viability than intact ones. This study was undertaken to compare the performance of intact frozen and thawed embryos with that of partially damaged embryos after removal of the necrotic blastomeres.
  
  
  METHODS
  Observational clinical series.
  
  
  METHODS
  Private hospital.
  
  
  METHODS
  Three hundred twenty-six infertile couples undergoing frozen embryo transfer.
  
  
  METHODS
  Removal of necrotic blastomeres from frozen-thawed human embryos.
  
  
  METHODS
  Pregnancy and implantations rates.
  
  
  RESULTS
  Outcomes of frozen embryo transfer cycles in which all embryos were fully intact (group 1) were compared with those in which all embryos have lost 1-2 blastomeres (group 2) or 3-4 blastomeres (group 3). Laser-assisted hatching was performed in all embryos, and necrotic blastomeres were removed from partially damaged embryos on this occasion. Only embryos that resumed mitotic activity after thawing were transferred. Comparable clinical pregnancy rates (PR) (38.7%, 39.6%, and 29.4%), delivery rates (34.4%, 34.0%, and 29.4%), and implantation rates (21.6%, 21.4%, and 17.2%) were obtained in groups 1, 2, and 3, respectively.
  
  
  CONCLUSIONS
  The developmental potential of partially damaged frozen and thawed embryos can be equivalent to fully survived embryos if the necrotic blastomeres are removed from the partially damaged embryos and only those of them that show post-thaw cleavage are selected for transfer.
authors.affiliation: Centre for Reproductive Medicine, European Hospital, Rome, Italy. rienzi.@icsiroma.it
authors.forename: Laura
authors.initials: L
authors.lastname: Rienzi
authors.forename: Filippo
authors.initials: F
authors.lastname: Ubaldi
authors.forename: Marcello
authors.initials: M
authors.lastname: Iacobelli
authors.forename: Maria Giulia
authors.initials: MG
authors.lastname: Minasi
authors.forename: Stefania
authors.initials: S
authors.lastname: Romano
authors.forename: Susanna
authors.initials: S
authors.lastname: Ferrero
authors.forename: Fabio
authors.initials: F
authors.lastname: Sapienza
authors.forename: Elena
authors.initials: E
authors.lastname: Baroni
authors.forename: Jan
authors.initials: J
authors.lastname: Tesarik
authors.forename: Ermanno
authors.initials: E
authors.lastname: Greco
mesh_terms: D000328:Adult; D001757:Blastomeres / Q000166:cytology / Q000473:pathology / Q000502:physiology*; D002478:Cells, Cultured; D016009:Chi-Square Distribution; D015925:Cryopreservation / Q000379:methods*; D046149:Embryo Culture Techniques / Q000379:methods*; D004624:Embryo Transfer; D004622:Embryo, Mammalian / Q000166:cytology / Q000473:pathology / Q000502:physiology*; D005260:Female; D006801:Humans; D007834:Lasers; D009336:Necrosis / Q000196:embryology / Q000473:pathology; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies