Correlation between embryo morphology and development and chromosomal complement

Abstract Objective To analyze the correlation between embryo morphology and the chromosomal status using the array comparative genomic hybridization [array comparative genomic hybridization (a-CGH)] technique for screening 23 chromosome pairs in a single blastomere biopsy from Day 3 embryos. Methods One thousand five hundred and fifty seven embryos were included from 203 cycle ICSI patients undergoing preimplantation genetic screening. The 23 chromosome pairs were analyzed by blastomere biopsy from day 3 embryos using a-CGH array method. Embryo development rate, fragmentation rate and chromosome status of the analyzed blastomeres were recorded and correlated with the aCGH results. Results The incidence of chromosomal abnormalities was significantly higher in slow-and fast cleaving embryos at day 3 after insemination. The incidence of fragmentation and the type of fragmentation was associated with an increased incidence of chromosomal abnormalities. The symmetry of the blastomeres also correlated with the aneuploidy rates. Conclusions Embryo development rate and morphological parameter such as degree, type of fragmentation and the symmetry of the blastomeres to a large extent reflect the cytogenetic status of the embryo and thus are important in the selection of embryos with the highest implantation potential.