Pre implantation genetic testing can be either PGS or PGD. In both the tests few cells are biopsied from embryo and sent for genetic testing to the Labs. The time taken for the report can be as little as 24 to 48 hours to a few weeks based on whether the sample is tested inhouse or needs to be processed at outsourced lab.
PGS is a process which detects chromosomal abnormality in the embryos where there is no family history of genetic condition. It is done to select the chromosomally normal embryos which can be used for couples with recurrent
IVF failures or those who wish to have a single embryo transfer to avoid the complications of multiple pregnancy. This is one of the few methods suggested to increase the implantation rate.
PGD is a process in which similar procedure is performed as in PGS as far as sampling a few cells from the embryo is concerned but here there is a family history of genetic disease and the cells are tested to screen that particular condition.
The downside of the PGT is the cost involved .Apart for that it would be a cost effective process only when we have been lucky enough to get more than 5 embryos which are atleast day 3 or still better day 5 or blastocyst.
As very small amount of cells are tested these tests have the potential of being not 100 % accurate rarely and thus Down’s screening test should be performed during pregnancy despite a negative PGT – A