Preimplantation Genetic Diagnosis (PGD) is a procedure used prior to implantation to help identify embryos that do not carry the gene for certain inherited diseases (such as cystic fibrosis and sickle cell anemia) to prevent these diseases or disorders from being passed on to the child.
Pre-implantation Genetic Screening (PGS) is a comprehensive chromosome screening that examines embryos for chromosomal abnormalities. All 24 chromosomes (22 autosomes plus X and Y) are examined to evaluate any gains or losses of chromosomes, also known as aneuploidy.
PGS allows for individuals and couples to achieve a healthy baby with additional information that may:
- Reduce the likelihood of miscarriage
- Decrease the risk of abnormal pregnancy
- Reduce the amount of time and additional costs inferred with multiple IVF cycles
- Increase the likelihood of pregnancy with single embryo transfers (eSET)
You can learn more by watching this excellent educational video on the PGS process:
The picture below shows an embryo at the blastocyst stage being biopsied for genetic screening: