Pre-implantation Genetic Diagnosis (PGD)  identifies the presence of genetic  or chromosomal abnormalities in embryos at  early stages of development, generated in vitro, by  couples at risk, before their implantation into the uterus.
PGD, may help to avoid therapeutic abortions, often psychologically devastating and not always ethically / morally accepted. PGD ​​combines IVF with innovative genetic diagnostic testing. The oocytes are fertilized  with paternal sperm and once fertilization is achieved, embryonic cells at the early stages of development are biopsied and removed for  diagnosis.