Center for Reproductive Medicine - Preimplantation Genetic Diagnosis (PGD)

Preimplantation Genetic Diagnosis (PGD)

Preimplantation Genetic Diagnosis (PGD) is genetic testing of three-day old embryos conceived with IVF to avoid transmission of familial single gene dominant or recessive diseases such as Cystic Fibrosis or Muscular Dystrophy, or structural chromosome defects like translocations or inversions. It may also be used to lower the age associated increased occurrence of chromosomal trisomies like Down syndrome.

With PGD, the embryologist removes one, sometimes two cells from each embryo created in the IVF cycle that grows to a certain stage. The cells are tested for abnormal genes or chromosomes. Only the embryos that have tested normal are transferred into the woman. Although PGD for single gene disorders is 99% accurate, it is possible to mislabel an embryo as normal when it is really abnormal (false negative). Therefore, couples often confirm the PGD diagnosis with chorionic villus sampling (CVS) or amniocentesis later in the pregnancy.

More recent data suggest that when screening embryos for the proper chromosome number it is more common than previously suspected to mislabel a chromosomally normal embryo as abnormal (false positive), thus possibly lowering the chance to conceive in that cycle.

PGD is still considered investigational.

PGD requires IVF. See IVF Overview.