Errors at mitotic segregation early in oogenesis and at first meiotic division in oocytes from donor females: comparative genomic hybridization analyses in metaphase II oocytes and their first polar body.

The aim of this work is to analyze, using the comparative genomic hybridization technique, the frequencies and the mechanisms involved in the production of aneuploidy events in donor oocytes. The results showed that 32.1% of them were aneuploid, with 51.7% of those originating from first meiotic division errors and 48.3% from the presence of aneuploid oogonium.