Preimplantation genetic diagnosis (PGD) enables the genetic study of embryos before they are transferred to the maternal uterus and, therefore, before implantation takes place. This entails an embryo biopsy. This involves an embryo biopsy, this being the extraction of one of the embryo’s cells, upon which the genetic study for various pathologies is carried out. With the result of this study, “normal or healthy” embryos are selected to be transferred to the uterus.
In some cases, there are couples with hereditary genetic diseases and PGD aims to select those embryos unaffected by the specific disease that the parents have or are carriers of. We call such cases PGD for monogenic diseases. In other cases, couples are at increased risk of generating embryos with anomalies in the number or the structure of chromosomes, which we call chromosomal PGD.