A linear karyotypic association between PB-I, PB-II and blastomere using sequentially performed comparative genome...

The importance of oocyte/embryo ploidy to achieve implantation and a subsequent pregnancy.

To correlate first and second polar bodies and day-3 blastomere ploidy, embryo morphology and biochemical (sHLA-G) characteristics with blastocyst development and in vitro pregnancy outcome.

All oocytes/zygotes and embryos were individually cultured to the blastocyst stage. PB-I, PB-II and blastomeres underwent complete karyotyping and sHLA-G expression was measured on day 2.

57 mature (MII) donor oocytes were obtained, 33/57 (57.9%) were aneuploid, 21/57 (36.8%) were euploid, and 3/57 (5%) were 'inconclusive'. No correlation was found between comparative genomic hybridization (CGH) status of PB-I, PB-II and the graduated embryo score. Furthermore, no correlation was established between PB-I CGH results and blastocyst morphology grade. There was a significant correlation between PB-I CGH and blastomere CGH results. Euploid and aneuploid PB-I developed into 58 and 67% blastocysts, respectively. ĸ statistics (>0.7) revealed a positive correlation between the ploidy of PB-I, PB-II and the blastomeres.

Following ICSI and sequential genetic karyotyping of the oocyte/zygote and subsequent blastomeres, the majority of oocytes fertilized and subsequent zygotes developed into blastocysts, despite their ploidy status. We therefore conclude that blastocyst development is not associated with ploidy.