Preimplantation Genetic Diagnosis (PGD)
Definition - What does Preimplantation Genetic Diagnosis (PGD) mean?
Preimplantation genetic diagnosis (PGD) is a medical procedure that allows for genetic testing of an embryo created during in vitro fertilization (IVF). This elective test is specific to carriers of known hereditary conditions. The test is designed to identify the presence of a specific genetic abnormality within the embryo, and provide the opportunity to avoid passing on a disorder or disease.
FertilitySmarts explains Preimplantation Genetic Diagnosis (PGD)
There are two types of preimplantation testing available, preimplantation genetic diagnosis, PGD, and preimplantation genetic screening, PGS. Individuals elect to undergo PGD when they know they are at risk for passing a specific hereditary disorder down to their child, while PGS is a general screening for individuals without any known genetic disorders.
PGD may be recommended for those who already have a biological child with a serious genetic disorder, who have previously ended pregnancies due to the presence of a serious genetic condition, and those with a family history of genetic disorders or chromosome conditions.
The process of PGD occurs during the IVF process. Once the eggs have been collected and fertilized they are considered an embryo. The embryo then spends several days in a lab, growing in its number of cells until about eight cells exist. Individual cells are then removed from each of the embryos and tested for the specific genetic condition. An embryo that does not test positive for the condition would then be transferred to the uterus to develop.
The risks of PGD coincide with standard risks of IVF. During the procedure, it is possible that testing may damage some embryos or results determine there are no embryos eligible for transfer to the uterus. Additionally, the test is not 100% reliable, and there is a possibility of passing conditions on to the child.