1. What is PGT?
Preimplantation genetic testing comprises a group of genetic assays used to evaluate embryos before transfer to the uterus.
2. How does it help?
PGT is done to test the genetics of the embryo prior to transfer.
Preimplantation genetic testing- Monogenic (PGT M) is targeted to single gene disorders
Preimplantation genetic testing- Aneuploidy (PGT A) is a broader test that screens for aneuploidy in all chromosomes, including the 22 pairs of autosomes and the sex chromosomes X and Y.
Preimplantation genetic testing-structural rearrangements (PGT SR) To test embryos that are at risk for chromosome gains and losses related to parental structural chromosomal abnormalities (eg, translocations, inversions, deletions, and insertions) Embryos that are genetically normal can thereby be selected for transfer.
3. For whom is it done?
PGD is used primarily for genetic disease prevention, by selecting only those embryos that do not have a known genetic disorder.
PGD may also be used to increase chances of successful pregnancy,
To match a sibling in HLA type in order to be a donor,
To have less cancer predisposition,
For sex selection in some countries where it is allowed
4. How is it done?
During IVF/ICSI cycle, patients embryos are assessed for biopsy on day 5.
During biopsy a single cell/cells are removed from the embryo
Following the embryo biopsy, embryos are cryopreserved and the biopsied cells are tested
Once the report is available the best embryos for transfer are selected.