title: Influence of embryo sex on development to the blastocyst stage and euploidy.
abstract: OBJECTIVE
  To compare the prevalence of blastocyst development and euploidy in XX versus XY embryos.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Boston IVF, a large university-affiliated reproductive medicine practice.
  
  
  METHODS
  All patients who underwent their first preimplantation genetic screening cycle between January 1, 2006, and December 31, 2007.
  
  
  METHODS
  In vitro fertilization and preimplantation genetic screening.
  
  
  METHODS
  Proportion of embryos that developed to the blastocyst stage by day 5 and prevalence of euploidy for chromosomes 8, 13, 14, 15, 16, 17, 18, 20, 21, and 22 in XX versus XY embryos.
  
  
  RESULTS
  Seven hundred fifty-eight embryos from 138 cycles in 138 patients were analyzed. Three hundred sixty-six (48%) were XX, and 392 (52%) were XY. XX and XY embryos were equally likely to develop to the blastocyst stage by day 5 and were equally likely to be euploid for the analyzed chromosomes.
  
  
  CONCLUSIONS
  Our data suggest that extending embryo culture to day 5 does not lead to sex selection and that euploidy and aneuploidy are not sex dependent.
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Eaton
authors.forename: Michele R
authors.initials: MR
authors.lastname: Hacker
authors.forename: C Brent
authors.initials: CB
authors.lastname: Barrett
authors.forename: Kim L
authors.initials: KL
authors.lastname: Thornton
authors.forename: Alan S
authors.initials: AS
authors.lastname: Penzias
mesh_terms: D001755:Blastocyst / Q000502:physiology*; D046149:Embryo Culture Techniques / Q000379:methods / Q000706:statistics & numerical data*; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro; D005820:Genetic Testing / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D011003:Ploidies; D011247:Pregnancy; D015995:Prevalence; D012189:Retrospective Studies; D012743:Sex Preselection / Q000706:statistics & numerical data*