title: Blastocyst culture and transfer increases the efficiency of oocyte donation.
abstract: OBJECTIVE
  To determine the impact of blastocyst transfer on an oocyte donation program.
  
  
  METHODS
  Retrospective review of embryo transfer in an IVF clinic.
  
  
  METHODS
  Private assisted reproductive technology unit.
  
  
  METHODS
  Two hundred and twenty nine patients undergoing oocyte donation.
  
  
  METHODS
  Culture of pronucleate embryos to either day 3 or day 5 followed by embryo transfer.
  
  
  METHODS
  Implantation rates, pregnancy rates, and multiple gestations were analyzed.
  
  
  RESULTS
  Implantation rates and pregnancy rates were significantly increased by moving to extended embryo culture and transfer on day 5. After day 3 transfers, implantation and pregnancy rates were 47.1% and 75%, respectively. In contrast, on day 5 these rates were increased to 65.8% and 87.6%. Concomitantly, there were significantly fewer embryos transferred on day 5 (2.1) compared to day 3 (3.2).
  
  
  CONCLUSIONS
  Blastocyst transfer is a highly effective treatment for patients who receive donor oocytes, allowing excellent pregnancy rates while significantly reducing the incidence of high-order multiple gestations.
authors.affiliation: Colorado Center for Reproductive Medicine, Englewood, Colorado 80110, USA. bschoolcraft@colocrm.com
authors.forename: W B
authors.initials: WB
authors.lastname: Schoolcraft
authors.forename: D K
authors.initials: DK
authors.lastname: Gardner
mesh_terms: D001755:Blastocyst / Q000502:physiology*; D046508:Culture Techniques; D010064:Embryo Implantation; D004624:Embryo Transfer; D005260:Female; D006801:Humans; D008423:Maternal Age; D018587:Oocyte Donation; D017063:Outcome Assessment, Health Care; D011247:Pregnancy; D011272:Pregnancy, Multiple; D012189:Retrospective Studies