what's the benefit?
The benefit of PGS/PGD are vast: they include a reduced risk of miscarriage and abnormal pregnancy, a decrease in the number of cycles to achieve a pregnancy (as well as the associated costs), an increase in the change of a successful pregnancy with a single embryo transfer, and an increase in the chance of delivering a healthy baby.
Genetic screening involves either PGS/PGD. PGS/PGD stands for Preimplantation Genetic Screening and Preimplantation Genetic Diagnosis. PGS/PGD uses the cells of the embryo to determine any chromosomal and genetic abnormalities, respectively, that might adversely affect the pregnancy.
How does it work?
Embryos are grown for 5-6 days in the laboratory – by day five, an embryo has well over 100 cells – before a small group of cells are removed via a biopsy procedure from the suitable embryos.
PGS tests for aneuploidy – an error in cell division that results in deleted, extra, or translocated chromosomes. PGS helps IVF physicians identify embryos that are chromosomally normal as these embryos are more likely to develop to term and result in the birth of a healthy baby. PGS scans 24 chromosome types: 22 non-sex chromosomes and two sex chromosomes (X and Y). Aneuploidy is usually not inherited and is associated with advanced maternal age.
PDG is used to screen embryos at risk of developing serious single gene (monogenetic) disorders, such as cystic fibrosis, Huntington disease, and spinal muscular dystrophies. The main benefit of PDG is for couples with family history with a high risk of severe monogenetic disorders, as PGD allows the specialists to determine which embryos are affected with a single gene disorder prior to implantation. This means that an embryo without those disorders are implanted.