Preimplantation Genetic Diagnosis (PGD) and Preimplantation Genetic Screening (PGS)

Preimplantation Genetic Diagnosis (PGD) is a test developed to help couples with a family history of genetically transmitted diseases to prevent this disease in their child. It is a procedure used in conjunction with in vitro fertilization (IVF) to screen embryos for a known chromosomal abnormality and a specific genetic disorder. Using PGD we can then transfer only chromosomally unaffected embryos (without the genetic disorder) into the uterus.

Preimplantation genetic screening (PGS) is a similar test but is not used to detect specific diseases. This test is a more general evaluation of the chromosomes of embryos to select chromosomally normal embryos for transfer. Although in standard IVF we select embryos based on their level of appropriate development and their appearance, this test actually allows us to determine which embryos are chromosomally normal. In this way it can allow us to select not only the embryos that initially act and appear normal but those that chromosomally are. It can increase pregnancy rates and live births per transfer and help to reduce recurrent pregnancy loss.