title: Impact of chromosomal abnormalities on preimplantation embryo development.
abstract: OBJECTIVE
  To evaluate the influence of numerical chromosomal abnormalities on preimplantation embryo development.
  
  
  METHODS
  This study includes 6936 embryos from 1245 women undergoing preimplantation genetic diagnosis (PGD). Indications for aneuploidy screening were: recurrent miscarriages, implantation failure, severe male factor, advanced maternal age, and mixed causes. Embryo biopsy was performed on day 3, and embryos were co-cultured until day 5, when embryo transfer was performed.
  
  
  RESULTS
  In the aneuploidy screening regimen, normal euploid embryos showed significantly higher blastocyst rates (68.2%) compared to chromosomally abnormal (42.8%, p < 0.0001) and mosaic (53.7%, p < 0.0001) embryos. Among aneuploid embryos for autosomes, higher blastocyst rates were observed in trisomies than monosomies, although only statistically significant in patients over 36 years of age (50.8 vs 38.9%; p < 0.0001). In contrast, in embryos with sex chromosomes aneuploidy, similar blastocyst rates were observed between trisomies and monosomy X.
  
  
  CONCLUSIONS
  Embryos with certain types of chromosomal abnormalities were negatively selected during preimplantation embryo development. Despite this selection, a remarkable percentage of chromosomally abnormal embryos can develop normally to blastocyst stage with high probability of implantation and pregnancy.
authors.affiliation: Instituto Valenciano de Infertilidad, Universidad de Valencia, Valencia, Spain. c.rubio@ivi.es
authors.forename: Carmen
authors.initials: C
authors.lastname: Rubio
authors.forename: Lorena
authors.initials: L
authors.lastname: Rodrigo
authors.forename: Amparo
authors.initials: A
authors.lastname: Mercader
authors.forename: Emilia
authors.initials: E
authors.lastname: Mateu
authors.forename: Pilar
authors.initials: P
authors.lastname: Buendía
authors.forename: Tugce
authors.initials: T
authors.lastname: Pehlivan
authors.forename: Thamara
authors.initials: T
authors.lastname: Viloria
authors.forename: Ma José
authors.initials: MJ
authors.lastname: De los Santos
authors.forename: Carlos
authors.initials: C
authors.lastname: Simón
authors.forename: José
authors.initials: J
authors.lastname: Remohí
authors.forename: Antonio
authors.initials: A
authors.lastname: Pellicer
mesh_terms: D000328:Adult; D000782:Aneuploidy; D001755:Blastocyst / Q000502:physiology*; D041321:Chromosomes, Human, X; D046508:Culture Techniques / Q000379:methods; D010064:Embryo Implantation / Q000235:genetics*; D047108:Embryonic Development / Q000235:genetics*; D005260:Female; D005307:Fertilization in Vitro; D005820:Genetic Testing / Q000379:methods*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008423:Maternal Age; D009030:Mosaicism; D011247:Pregnancy; D019836:Preimplantation Diagnosis / Q000379:methods*; D014314:Trisomy