What is PGD Testing?
Preimplantation Genetic Diagnosis, commonly known as PGD, is a series of tests that are commonly offered in conjunction with your IVF cycle. These tests can be used to identify and diagnose potential chromosomal abnormalities in embryos before they’re ever transferred to a waiting uterus. This can greatly reduce selective termination in the event an abnormality is found later in the pregnancy.
It is worth noting the differences between a PGD and PGS test. While the PGD will be able to predict the presence pf specific diseases or disorders, the PGS (Preimplantation Genetic Screening) will look for a multitude of abnormalities at once. The purpose of the two tests differs in that one seeks to identify and diagnose specific conditions where the other seeks only to improve chances at a live birth based on severe chromosomal abnormalities.
The PGD test is completed after the eggs are retrieved from the intended mother or egg donor and fertilized to create the embryo. A doctor will then remove one or more cells from the embryo for closer examination. The test looks first at the number of chromosomes in the embryo. A typical human has 23 pairs of chromosomes for a total of 46. A PGD will be able to determine if Down Syndrome (marked by the presence of one additional chromosome) or any other chromosomal abnormalities are present. In total, PGD testing can identify more than 100 different genetic conditions.
Of the 100 different conditions that are able to be accurately identified, key inherited diseases include:
- Cystic Fibrosis
- Huntington’s disease
- Sickle cell disease
- BRCA1 mutations (a cancer causing gene)
- Fragile X
- Myotonic Dystrophy
While this test is available to all Growing Generations’ clients, those who benefit the most greatly include:
- Those who are donating their own genetics to embryo creation and are known carriers of genetic abnormalities
- Those who are donating their own genetics and have a familial history of genetic or chromosomal abnormalities or inherited diseases
- An intended mother of advanced maternal age (generally anything over 35 years)
- An intended mother with a history of repeated miscarriages
The PGD procedure is not known to cause any increased likelihood of birth defects. Currently the only known risks are potential damage to the embryo in the biopsy phase or a misdiagnosis, though both occurrences are believed to be rare.