title: Effect of laser-assisted hatching and necrotic blastomere removal on the development of vitrified-warmed four-cell mouse embryos.
abstract: OBJECTIVE
  To investigate the effect of laser-assisted hatching and necrotic blastomere removal on the development of vitrified-warmed mouse embryos.
  
  
  METHODS
  The vitrified-warmed four-cell stage mouse embryos were divided into five groups; vitrified intact with no laser-assisted hatching, vitrified intact with laser-assisted hatching, vitrified damaged with neither laser assisted hatching nor necrotic blastomere removal, vitrified damaged with laser-assisted hatching, and vitrified damaged with necrotic blastomere removal. Thereafter blastocyst formation, blastomere and apoptotic cell number within all groups were statistically compared.
  
  
  RESULTS
  The rate of blastocyst formation showed a significant improvement in the group vitrified intact with laser-assisted hatching. However, neither laser-assisted hatching nor necrotic blastomere removal can improve a delayed vitrified-warmed damaged embryos in term of blastocyst formation and total cell number. Nevertheless, apoptotic cell number was significantly reduced after application of both techniques.
  
  
  CONCLUSIONS
  Laser-assisted hatching can improve the development of vitrified-warmed intact four-cell stage mouse embryos, whereas necrotic blastomere removal has no significant effect on the development of vitrified-warmed four-cell stage damaged embryos.
authors.affiliation: Department of Anatomy, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, PO Box 14115-111, Iran.
authors.forename: Rouhollah
authors.initials: R
authors.lastname: Fathi
authors.forename: Mojtaba Rezazadeh
authors.initials: MR
authors.lastname: Valojerdi
authors.forename: Poopak
authors.initials: P
authors.lastname: Eftekhari-Yazdi
mesh_terms: D000818:Animals; D017209:Apoptosis; D001755:Blastocyst / Q000502:physiology*; D001757:Blastomeres / Q000166:cytology*; D015925:Cryopreservation / Q000379:methods*; D046149:Embryo Culture Techniques; D004622:Embryo, Mammalian / Q000166:cytology*; D005260:Female; D006358:Hot Temperature; D020287:In Situ Nick-End Labeling; D007834:Lasers; D051379:Mice; D015233:Models, Statistical; D009336:Necrosis; D013997:Time Factors