title: Preimplantation genetic testing: polar bodies, blastomeres, trophectoderm cells, or blastocoelic fluid?
abstract: OBJECTIVE
  To investigate the blastocoelic fluid (BF) for the presence of DNA that could be amplified and analyzed; the extent to which its chromosomal status corresponds to that found in trophectoderm (TE) cells, polar bodies (PBs), or blastomeres; and the identification of segmental abnormalities.
  
  
  METHODS
  Longitudinal cohort study.
  
  
  METHODS
  In vitro fertilization unit.
  
  
  METHODS
  Fifty-one couples undergoing preimplantation genetic screening or preimplantation genetic diagnosis for translocations by array-comparative genomic hybridization on PBs (n = 21) or blastomeres (n = 30).
  
  
  METHODS
  BFs and TE cells were retrieved from 116 blastocysts, whose chromosome status had already been established by PB or blastomere assessment. Separate chromosome analysis was performed in 70 BFs.
  
  
  METHODS
  Presence of DNA in BFs, evaluation of the chromosome condition, and comparison with the diagnosis made in TE cells and at earlier stage biopsies.
  
  
  RESULTS
  DNA detection was 82%, with a net improvement after refinement of the procedure. In 97.1% of BFs, the ploidy condition corresponded to that found in TE cells, with one false positive and one false negative. The rate of concordance per single chromosome was 98.4%. Ploidy and chromosome concordance with PBs were 94% and 97.9%, respectively; with blastomeres, the concordances were 95% and 97.7%, respectively. Segmental abnormalities, which were detected in PBs or blastomeres of 16 blastocysts, were also identified in the corresponding BFs.
  
  
  CONCLUSIONS
  BF represents to a good extent the blastocyst ploidy condition and chromosome status when compared with TE cells. If the proportion of clinically useful BFs is improved, blastocentesis could become the preferred source of DNA for chromosomal testing.
authors.affiliation: SISMER, Reproductive Medicine Unit, Bologna, Italy.
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Magli
authors.affiliation: SISMER, Reproductive Medicine Unit, Bologna, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Pomante
authors.affiliation: SISMER, Reproductive Medicine Unit, Bologna, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Cafueri
authors.affiliation: SISMER, Reproductive Medicine Unit, Bologna, Italy.
authors.forename: Marzia
authors.initials: M
authors.lastname: Valerio
authors.affiliation: SISMER, Reproductive Medicine Unit, Bologna, Italy.
authors.forename: Andor
authors.initials: A
authors.lastname: Crippa
authors.affiliation: SISMER, Reproductive Medicine Unit, Bologna, Italy.
authors.forename: Anna P
authors.initials: AP
authors.lastname: Ferraretti
authors.affiliation: SISMER, Reproductive Medicine Unit, Bologna, Italy. Electronic address: luca.gianaroli@sismer.it.
authors.forename: Luca
authors.initials: L
authors.lastname: Gianaroli
mesh_terms: D000328:Adult; D001706:Biopsy; D001755:Blastocyst / Q000737:chemistry* / Q000473:pathology; D001757:Blastomeres / Q000737:chemistry* / Q000473:pathology; D002869:Chromosome Aberrations; D025063:Chromosome Disorders / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D055028:Comparative Genomic Hybridization; D004247:DNA / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D004475:Ectoderm / Q000737:chemistry* / Q000473:pathology; D046149:Embryo Culture Techniques; D045604:Extracellular Fluid / Q000737:chemistry* / Q000166:cytology; D005260:Female; D005307:Fertilization in Vitro; D005819:Genetic Markers; D005820:Genetic Testing; D006801:Humans; D008137:Longitudinal Studies; D011003:Ploidies; D059705:Polar Bodies / Q000737:chemistry* / Q000473:pathology; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D011247:Pregnancy; D019836:Preimplantation Diagnosis / Q000379:methods*; D014327:Trophoblasts / Q000737:chemistry* / Q000473:pathology
chemical_list: D005819:Genetic Markers; D004247:DNA
keywords: Blastocyst; blastocoel; blastomere; polar bodies; preimplantation genetic screening