CGH (Comparative Genomic Hybridization) viability as embryo genetic technology of analysis

In recent years, embryonic genetic analysis has been performed mainly by embryo biopsy on the third day of development, where one or two blastomeres are studied using the FISH technique. However, this technique, can not analise the whole cell genome and can not rule out mosaicism, since only a small sample is analyzed. As the CGH (Comparative Genomic Hybridization) and aCGH (microarray analysis) promotes an evaluation of the entire genome from a single cell DNA sample hybridized, allows the diagnosis of losses, gains, deletions, translocations and gene amplifications. Therefore, represents a good alternative to genetic screening in women with advanced age, implantation failure, recurrent abortion and in cases of severe male infertility factor. To this end, the blastocyst biopsy is preferred. Besides the natural selection of embryos reaching the blastocyst stage, the trophectoderm biopsy allows the study of 5 to 10 cells, facilitating the detection of mosaicism. However, as the techniques previously used, it can not detect balanced genomic alterations, gene defects and ploidy. The better selection of embryos enables single embryo transfer, reducing the rates of multiple births and pregnancy risk. However, more randomized studies are needed to establish this technique as the gold standard in genetic evaluation stage.