First Babies Born after Total Genetic Screening
Babies in Germany and Italy are the first to enter this world after total screening for chromosomal deficiencies. This is according to ESHRE, the European Society of Human Reproduction and Embryology.
Three newborn babies—a pair of twins and a singleton—are the first deliveries from a test program using CGH, Comparative Genomic Hybridization, to comprehensively screen eggs before transferring them into a woman.
Until now, says the chairman of ESHRE, Luca Gianaroli, more than 60 percent of embryos transferred have failed to evolve into lasting pregnancies due to chromosomal abnormalities. The new technique offers to substantially increase successful impregnations—something that will especially benefit older women and women with high abortion rates.
Another big advantage of CGH, according to ESHRE, is that cells are tested prior to the transfer. This means it will no longer be necessary to extract tissue samples from the developing embryo. Using CGH is also more accurate than the biopsies presently used because cells extracted from the embryo can not be trusted to tell the full story about its genome.
Due to so-called chromosome mosaicism—a phenomenon where different cells from the same egg develop different chromosomal makeups—a cell biopsy will not be able to guarantee that later cells will not have chromosomal deficiencies. Down Syndrome is a common pathology related to chromosome mosaicism.
“Now we have a new technology in array CGH and our hopes are that this will finally provide a reliable means of assessing the chromosomal status of the embryos we transfer,” says Luca Gianaroli from ESHRE.