title: Factors relating to a successful cryopreserved blastocyst transfer program.
abstract: OBJECTIVE
  To review the authors' experience in a successful frozen blastocyst program.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  University IVF program.
  
  
  METHODS
  Women of all ages undergoing 64 frozen blastocyst nondonor thaw cycles.
  
  
  METHODS
  Thaw cycles with day 5 or day 6 frozen blastocysts replaced into luteal day 5 endometrium in natural or programmed cycles; cryopreservation of blastocysts by Menezo two-step protocol and Testart slow cool program; thawing by two step thaw protocol.
  
  
  METHODS
  Implantation, clinical pregnancy, and delivery rates.
  
  
  RESULTS
  The implantation rate was 16% and was similar with day 5 frozen blastocysts and day 6 frozen blastocysts cycles. The clinical pregnancy rate was 36% and the delivery rate was 27%, with no significant difference between day 5 and 6 blastocysts.
  
  
  CONCLUSIONS
  Blastocyst cryopreservation is a viable option for patients of all ages and complements fresh blastocyst culture and transfer. The presence of good quality blastocysts for freezing on day 5 and day 6 yields comparable results and is critical for the success of thaw cycles.
authors.affiliation: Department of Gynecology and Obstetrics, Stanford University Medical Center, Stanford, California 94305, USA. behr@stanford.edu
authors.forename: Barry
authors.initials: B
authors.lastname: Behr
authors.forename: Janice
authors.initials: J
authors.lastname: Gebhardt
authors.forename: Jennifer
authors.initials: J
authors.lastname: Lyon
authors.forename: Amin A
authors.initials: AA
authors.lastname: Milki
mesh_terms: D001755:Blastocyst; D015925:Cryopreservation; D010064:Embryo Implantation; D004624:Embryo Transfer; D005260:Female; D006358:Hot Temperature; D006801:Humans; D011247:Pregnancy; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome