[Preimplantation genetic testing: legal and ethical aspects in clinical practice].

In Switzerland, since modifications of the law regulating reproductive medicine introduced the 1rst of September 2017, preimplantation genetic testing (PGT) has been legalised. Infertile couples undergoing in vitro fertilization (IVF) can benefit from this technology by detecting which embryos are aneuploid (ie abnormal number of chromosomes, PGT-A). This is performed in order to transfer euploid embryos (normal number of chromosomes) and to optimise success, though data are limited. Couples at risk of transmitting a severe monogenic disease or unbalanced translocation can undergo PGT for monogenic disease or chromosomal structural rearrangements (PGT-M/SR). These tests are subject to strict legal criteria. Their clinical application needs to be approved through a multidisciplinary approach taking into account legal and ethical issues while respecting the autonomy of the couples.