title: Ploidity and chromatin status of human oocytes after failed in vitro fertilization.
abstract: OBJECTIVE
  To investigate the chromatin status of oocytes and their ploidity in order to consider possible genetic reasons for their unsuccessful fertilization in vitro.
  
  
  METHODS
  Eighty-six unfertilized in vitro human oocytes were scored in six groups according to their chromatin status. Analysis was performed by cytogenetics and by fluorescent in situ hybridization (FISH).
  
  
  RESULTS
  73.26% of oocytes were successfully analyzed: 44.19% by classical cytogenetics and 17.44% by FISH. 11.63% of the analyzed cells contained sperm chromosomes with premature chromosome condensation (PCC). Among karyotyped oocytes, a high aneuploidy rate was found (5.26% haploid abnormal, 21.05% hypohaploid, 36.84% hyperhaploid and 7.89% diploid). FISH for chromosomes X, 1, 5 and 19 performed on unsuitable for karyotyping metaphase plates revealed 13.33% aneuploid cells.
  
  
  CONCLUSIONS
  Analysis of fertilization failure could be more informative when a combination of methods is applied.
authors.affiliation: Human IVF Unit Technobioassistance, Department of Biology, Medical Faculty, Medical University, 1 St. George Sofiisky Street, 1431 Sofia, Bulgaria. zhivkova@medfac.acad.bg
authors.forename: Ralitsa S
authors.initials: RS
authors.lastname: Zhivkova
mesh_terms: D000782:Aneuploidy; D002843:Chromatin / Q000235:genetics / Q000648:ultrastructure*; D002869:Chromosome Aberrations; D025063:Chromosome Disorders / Q000648:ultrastructure; D002875:Chromosomes / Q000648:ultrastructure*; D003582:Cytogenetics; D005307:Fertilization in Vitro; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D009865:Oocytes / Q000648:ultrastructure*; D017211:Treatment Failure
chemical_list: D002843:Chromatin