Preimplantation genetic diagnosis of aneuploidy: Were we looking at the wrong chromosomes?

Purpose: Our purpose was to study aneuploidy frequencies of chromosomes 1, 4, 6, 7, 14, 15, 17, 18, and 22 in cleavage-stage embryos. These frequencie s were compared to spontaneous abortion data to determine differences in su rvival rate of their aneuploidies. Methods: One hundred ninety-four embryos were analyzed with multicolor fluo rescence in situ hybridization. Embryos were divided into three maternal ag e groups: 20 to 34.9 years, (2) 35 to 39.9 years, and (3) 40 years and olde r. Embryos were also divided into two developmental and morphological group s: arrested and nonarrested embryos. Results: The rare of aneuploidy was 14.51%, 14.10%, and 31.48% for age grou ps 1, 2, and 3, respectively (P < 0.005). The chromosomes most frequently i nvolved in aneuploidy events were 22, 15, 1, and 17. Conclusions: The chromosomes most involved in spontaneous abortions are not necessarily the ones causing a decrease in implantation rates with materna l age. Other aneuploidies, such as for chromosomes 1 and 17, may seldom imp lant or die shortly after implantation.