Embryo Project Encyclopedia

Preimplantation genetic diagnosis (PGD) involves testing for specific genetic conditions prior to the implantation of an embryo in the uterine wall. This form of genetic screening has been made possible by the growth of in-vitro fertilization (IVF) technology, which allows for the early stages of development to occur in a laboratory dish rather than in vivo. The purpose of PGD is to identify what are considered to be abnormal embryos in order to select the most desirable embryos for implantation. Diagnosis is comprised of two steps: extraction of one or two cells from an IVF-produced embryo, and application of the PGD test. PGD is important to embryology because it has advanced IVF results and allowed couples more opportunities to deliver a child to term; however, it has also created much controversy.