During the performance of assisted reproduction procedures, the best embryo is selected for transfer into the mother’s uterus. The selection is based on the “look” of the embryo shortly before transfer. As a matter of fact, waiting time normally stretches until day 5 of embryo culture in order to enhance the potential of the selected embryo and its synchronisation with the endometrium.
Sometimes the selection is favoured by performing a Comprehensive Chromosome Screening (PGS/PGT-A/CCS) test. Thanks to this technique, we can find out if an embryo has all the chromosomes in their exact number, in other words, if it is chromosomally normal. In this way, the selection is both morphological (external look) and chromosomal (internal look).
To be able to analyse the embryo we must first biopsy it (take a cell sample) without affecting its development and subsequent implantation. Biopsy techniques have been evolving until the process has been optimised. […]