IVF Spring > Genetics Testing Programme > Pre-implantation Genetic Screening (PGS)
Pre-implantation Genetic Screening (PGS)
During an IVF procedure, it is important to only use the highest quality eggs to fertilize and use the best embryos to transfer to the womb. To know more about the embryos there is a procedure known as pre-implantation genetic screening. PGS is the testing of the embryos chromosomal coding. To ensure that it is normal. Pre-Implantation Genetic screening helps identifies chromosomal deficiencies such as an aneuploidy (extra or missing chromosome).
PGS is the best way to choose viable embryos to transfer to the uterus. PGS is followed by an array-CGH test which is the testing of the cells to find the number of chromosomes. Abnormalities indicate an issue with the embryo.
Advantages of Pre-implantation Genetic Screening (PGS)
Better IVF succeess rates
Embryos that are screened for chromosomal abnormalities before implantation have a higher rate of IVF success. This is because it gives priority for only those embryos that have the correct number of chromosomes the priority of transfer to the womb.
Better diagnosis & assessment
In PGS the chromosome abnormalities that could cause Down syndrome can be identified also accurate assessment of embryos is possible.
Help to reduce miscarriage
Transferring genetically normal embryos improves the implantation success and reduces the chances of miscarriages.
Who is Pre-implantation Genetic Screening (PGS) suitable for?
As the woman grows older the quality of her eggs deteriorates. It is more likely for elder women to have chromosomal abnormalities in her eggs than younger women. Having said that, embryo genetic screening test is for all women who are undergoing an IVF procedure. It helps the fertility experts pick the best embryos to transfer to the uterus. PGS may also be suggested in some cases as:
- If you have a history of hereditary chromosome abnormalities
- If there is risk of your sperm carrying abnormal genes
- If you are suffering from consecutive miscarriages or unexplained failed IVF
How safe is Pre-implantation Genetic Screening (PGS) for embryos?
Performing PGS on embryos at blastocyst stage has little or no effect on the successful development of the embryo. This is because an embryo developed to this stage has many more cells, which can be extracted without affecting an embryo’s potential for pregnancy. The cells which are extracted during PGS are called trophectoderm cells, which will go on to form the placenta.
How Pre-implantation Genetic Screening (PGS)Works?
- External blastocyst embryo cells are selected for examination
- Extracted cells are sent to laboratory for chromosome sequencing
- If all 23 sets of chromosomes are identified the embryo is considered genetically normal and ready for transfer
- Based on the genetic results, you and your medical team will select which embryo to transfer