Preimplantation Genetic Screen (PGS) is a medical procedure in IVF treatment. By this advanced screening, the embryos are tested for any abnormality in chromosomes, to select the right and healthy ones for planting and achieve successful pregnancy. It is also known as aneuploidy screening.
On day 5 or 6 of the embryos after IVF/ICSI, when the embryos have reached the blastocyst stage, embryo biopsy is performed by our embryologists in the IVF lab. Day 3 embryos can also be biopsied and sent for PGS. Few cells from the outer layer (trophectoderm) is removed with the help of a biopsy pipette under the microscope. A laser beam is shot onto the specific area of the layer and cells are removed from the area. These cells are then transferred into a special biopsy kit which is to be kept at -20 degree Celsius. The cells are then sent to a special genetic laboratory where the chromosomal abnormalities are tested in the embryo using the most advanced techniques.
The embryos are then immediately vitrified and stored. When we get the results of the PGS, chromosomally normal embryos are thawed and transferred into the uterus of the intended mother. The best embryos among these chromosomally normal embryos are selected for the transfer.