PREIMPLANTATION GENETIC DIAGNOSIS (PGD) is also known as genetic embryo screening. PGD is the testing of embryos using certain procedures prior to implantation within the uterus. PGD can also be performed on oocytes prior to fertilization. PGD is used as a testing option instead of prenatal genetic diagnosis that traditionally occurs after the fetus is in utero. PGD tests for genetic conditions that have the potential to cause the disease. The advantage of PGD is that the testing is performed prior to implantation. Embryos that are affected are identified and not implanted. PGD can only be used for women who are achieving pregnancy through in vitro fertilization (IVF). The main advantage is that it reduces selective termination of affected fetuses.

In PGD, polymerase chain reaction (PCR) ...