Analysis of human unfertilized oocytes and pronuclear zygotes--correlation between chromosome/chromatin status and patient-related factors.

Objective: The objective was to evaluate the relationship between ploidy and chromatin status of human unfertilized oocytes/zygotes and infertility history, female age, and stimulation regimens.

Study Design: Two hundred and eighty-nine unfertilized oocytes and 63 zygotes were subjected to cytogenetic analysis: karyotyping for oocytes and fluorescent in situ hybridization (FISH) analysis for zygotes. Ploidy and chromosome/chromatin status were analyzed according to stimulation regimen, female age, and infertility history.

Chromosomal disorders and nuclear and cell destruction in cleaving human embryos.

Three types of defects of preimplantation embryogenesis contribute to the developmental arrest of cleaving human embryos: blastomere fragmentation, abnormal nuclear status and chromosomal disorders. Data concerning the relation and succession of these abnormalities during first mitotic cycles of the human zygote are controversial and mainly empirical at present. In this study we have performed simultaneous evaluation of blastomere fragmentation, nuclear apoptotic changes and the ploidy of four chromosomes (1, 5, 19 and X or 18, 21, X and Y) in 193 human embryos.