title: Clinical application of comprehensive chromosomal screening at the blastocyst stage.
abstract: OBJECTIVE
  To evaluate a new strategy for comprehensive chromosome screening at the blastocyst stage.
  
  
  METHODS
  Clinical research study.
  
  
  METHODS
  An IVF clinic and a specialist preimplantation genetic diagnosis laboratory.
  
  
  METHODS
  Forty-five infertile couples participated in the study. The mean maternal age was 37.7 years, and most couples had at least one previous unsuccessful IVF treatment cycle (mean 2.4).
  
  
  METHODS
  This study used a novel chromosome screening approach, combining biopsy of several trophectoderm cells on day 5 after fertilization and detailed analysis of all 24 types of chromosome using comparative genomic hybridization.
  
  
  METHODS
  Proportion of embryos yielding a diagnostic result, aneuploidy rate, implantation rate, and pregnancy rate.
  
  
  RESULTS
  A diagnosis was obtained from 93.7% of embryos tested. The aneuploidy rate was 51.3%. The probability of an individual transferred embryo forming a pregnancy reaching the third trimester/birth was 68.9%, an implantation rate 50% higher than contemporary cycles from the same clinic. The pregnancy rate was 82.2%.
  
  
  CONCLUSIONS
  The comprehensive chromosome screening method described overcomes many of the problems that limited earlier aneuploidy screening techniques and may finally allow preimplantation genetic screening to achieve the benefits predicted by theory. The high embryo implantation rate achieved is particularly encouraging and, if confirmed in subsequent studies, will be of great significance for IVF clinics attempting to reduce the number of embryos transferred or to implement single embryo transfer.
authors: Colorado Center for Reproductive Medicine, Lone Tree, Colorado, USA.
authors: William B
authors: WB
authors: Schoolcraft
authors: Elpida
authors: E
authors: Fragouli
authors: John
authors: J
authors: Stevens
authors: Santiago
authors: S
authors: Munne
authors: Mandy G
authors: MG
authors: Katz-Jaffe
authors: Dagan
authors: D
authors: Wells
mesh_terms: D000328:Adult; D000782:Aneuploidy; D001755:Blastocyst; D002875:Chromosomes / Q000235:genetics*; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods; D005820:Genetic Testing / Q000379:methods*; D006801:Humans; D008297:Male; D017063:Outcome Assessment, Health Care; D011247:Pregnancy; D018873:Pregnancy Rate; D019836:Preimplantation Diagnosis / Q000379:methods*