Fig. 1. Confirmation of day 3 PGS results. Representative FISH confirmatoryresults of an embryo found to be aneuploid by PGS performed on 2 blastomeres.Reanalysis on 9 cells demonstrated uniform aneuploidy most likely due to ameiotic error.ploidy resulting from meiotic errors is expressed both in day3 PGS analysis, as well as in reanalysis on day 5. Fig. 1 demon-strates trisomy 16 in two blastomeres at day 3 analysis (A),confirmed by day 5 reanalysis on 9 cells (B). A meiotic error ismost likely the cause of this aberration since it was demonstrateduniformly in all the analyzed cell