Ploidity and chromatin status of human oocytes after failed in vitro fertilization.
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.
Zhivkova
Ralitsa S
RS
Human IVF Unit Technobioassistance, Department of Biology, Medical Faculty, Medical University, 1 St. George Sofiisky Street, 1431 Sofia, Bulgaria. zhivkova@medfac.acad.bg
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
D002843:Chromatin