title: In vitro and in vivo viability of human blastocysts collapsed by laser pulse or osmotic shock prior to vitrification.
abstract: OBJECTIVE
  This study was designed to investigate whether artificial shrinkage, induced by a laser pulse or hyperosmotic sucrose solutions, improves in vitro survival and/or implantation of vitrified-warmed human expanded blastocysts.
  
  
  METHODS
  Before Cryotop vitrification, the blastocoelic cavity was collapsed either by a laser pulse or sucrose solutions. Non-treated blastocysts were used as control. Post-warm blastocyst survival and implantation after transfer were examined. Implantation rate outcome was retrospectively analyzed by morphological grading and developmental kinetics of post-warm blastocysts.
  
  
  RESULTS
  Survival rates in the three groups were high. Implantation rates in the laser-pulse group (59.7%) were comparable with those in the sucrose group (49.3%), and were significantly higher than those in the control group (34.2%). The proportion of blastocysts showing fast development tended to be higher when the blastocysts underwent artificial shrinkage treatment before vitrification. There was no clear correlation between morphology of post-warm blastocysts and implantation rate.
  
  
  CONCLUSIONS
  Artificial shrinkage treatment before vitrification is associated with an increased probability of fast-developing embryos, resulting in higher implantation rates.
authors.affiliation: Yamashita Ladies' Clinic, Kobe, Hyogo, 651-0086, Japan. hiwayama@hotmail.co.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Iwayama
authors.forename: Shinichi
authors.initials: S
authors.lastname: Hochi
authors.forename: Masanori
authors.initials: M
authors.lastname: Yamashita
mesh_terms: D000328:Adult; D001755:Blastocyst / Q000166:cytology* / Q000502:physiology; D002470:Cell Survival; D015925:Cryopreservation / Q000379:methods; D003451:Cryoprotective Agents / Q000494:pharmacology; D046508:Culture Techniques; D010064:Embryo Implantation; D047108:Embryonic Development; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D007834:Lasers; D009997:Osmotic Pressure; D011247:Pregnancy; D011256:Pregnancy Outcome; D012189:Retrospective Studies; D056826:Single Embryo Transfer / Q000379:methods; D058989:Vitrification
chemical_list: D003451:Cryoprotective Agents