Pre-implantation Genetic Diagnosis (PGD) is a method that enables genetic diagnosis of a pre-embryo in an in-vitro fertilization process, in order to enable the birth of healthy babies in families that have high risk (high probability) for transmitting a serious genetic disease to the baby.

The first stage of pre-implantation genetic diagnosis is in-vitro fertilization, followed by genetic testing of the pre-embryos that are obtained, and transfer to the uterus of a pre-embryo that does not have the genetic disease that was tested for. During the pregnancy, it is recommended to perform prenatal testing (chorionic villus sampling test or amniotic fluid test) for final confirmation that the fetus is free of the disease that was tested for.

Pre-implantation Genetic Diagnosis (PGD) is today considered to be one of the practical options for couples who are at high risk for giving birth to a baby with a chromosomal abnormality or a genetic disease. This is because the process allows pregnancies to be achieved with healthy fetuses, and avoids the need for pregnancy termination, a procedure that constitutes a problem for many couples for religious, ethical and/or moral reasons. 

 So far, many children have been born who do not suffer from the familial disease after having undergone pre-implantation genetic diagnosis, which indicates that the technology is reliable.