title: An efficient protocol for the detection of chromosomal abnormalities in spontaneous miscarriages or foetal deaths.
abstract: OBJECTIVE
  Characterization of chromosomal abnormalities in 232 spontaneous miscarriages or foetal deaths using both classical and molecular cytogenetics.
  
  
  METHODS
  Chromosomal abnormalities are responsible for 40-50% of all early pregnancy losses. Conventional cytogenetics is associated with 10-40% of culture failure. Comparative genomic hybridization (CGH) is a DNA-based technique that screens chromosome imbalances in the whole genome and may overcome this problem, although additional methods are required to distinguish between different ploidies, mosaicisms and maternal cell contamination. For a full characterization of chromosomal aberrations in 232 spontaneous miscarriages or foetal deaths we applied a sequential protocol that uses conventional cytogenetics, plus CGH and touch fluorescence in situ hybridization (Touch FISH).
  
  
  RESULTS
  Successful karyotyping was obtained in 173/232 (74.6%) of the cases, 66/173 (38.2%) of which had an abnormal chromosomal complement. CGH and Touch FISH analyses revealed another 19 abnormal cases in the 63 failures of culture. Overall there were 85/233 (36.6%) cases with an abnormal chromosomal complement, with examples from all three trimesters. Comparing cases, with or without chromosomal abnormalities, no statistical differences were found between women with one or recurrent miscarriages. On the contrary, significant differences were found comparing mean maternal ages or mean gestational ages, in cases with or without chromosomes abnormalities.
  
  
  CONCLUSIONS
  Adopting this sequential protocol, chromosomal complement information was available even in cases with culture failure.
authors.affiliation: Department of Genetics, Faculty of Medicine, University of Porto, Porto, Portugal. sdoria@med.up.pt
authors.forename: Sofia
authors.initials: S
authors.lastname: Dória
authors.forename: Filipa
authors.initials: F
authors.lastname: Carvalho
authors.forename: Carla
authors.initials: C
authors.lastname: Ramalho
authors.forename: Vera
authors.initials: V
authors.lastname: Lima
authors.forename: Tânia
authors.initials: T
authors.lastname: Francisco
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Machado
authors.forename: Otília
authors.initials: O
authors.lastname: Brandão
authors.forename: Mário
authors.initials: M
authors.lastname: Sousa
authors.forename: Alexandra
authors.initials: A
authors.lastname: Matias
authors.forename: Alberto
authors.initials: A
authors.lastname: Barros
mesh_terms: D000022:Abortion, Spontaneous / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D002869:Chromosome Aberrations; D055028:Comparative Genomic Hybridization; D005260:Female; D005313:Fetal Death / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008875:Middle Aged; D011247:Pregnancy