title: Freezing cocultured human blastocysts.
abstract: OBJECTIVE
  To determine the possibility of obtaining good pregnancy rates (PRs) after freezing and thawing cocultured blastocysts.
  
  
  METHODS
  Human blastocysts were frozen first according to a protocol available from literature. Two other protocols including the addition of glycerol were designed to improve the results.
  
  
  METHODS
  All the patients were under clinical management at the Institut Rhonalpin pour l'Etude de la Reproduction Humaine in Lyons, France.
  
  
  METHODS
  Patients involved in the in vitro fertilization program have had their supernumerary embryos frozen according to the three protocols presented here.
  
  
  METHODS
  Embryo recovery after freezing and thawing. Clinical and ongoing pregnancies after embryo transfer (ET).
  
  
  RESULTS
  A protocol including sucrose addition and reduction of steps in the preparation of the blastocysts for freezing gave us a 21% PR per transfer (15 ongoing) of 101 transfers (106 thawings).
  
  
  CONCLUSIONS
  Freezing of cocultured human blastocysts allow good PRs. This can represent an alternative for repeated failures of ETs at early stages.
authors.affiliation: Institut Rhonalpin pour l'Etude de la Reproduction Humaine/Fondation Mérieux, Bron, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Ménézo
authors.forename: B
authors.initials: B
authors.lastname: Nicollet
authors.forename: N
authors.initials: N
authors.lastname: Herbaut
authors.forename: D
authors.initials: D
authors.lastname: André
mesh_terms: D001755:Blastocyst / Q000502:physiology*; D015925:Cryopreservation; D046508:Culture Techniques; D010064:Embryo Implantation; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D005615:Freezing; D006801:Humans; D011247:Pregnancy