Preimplantation Genetic Testing is a reproductive technology used along with an IVF cycle to increase the potential for a successful pregnancy and delivery of a healthy child.
PGT is a genetic test on cells extracted from 5-6 days old embryos ( called blastocyst stage ), to help select the best embryo(s) in order to achieve higher pregnancy rate , reduce the miscarriage rate and also to avoid a genetic disease in the baby if either one or both parents are known to be a carrier of a specific genetic disease.
- PGT-A ( A=aneuploidy ) screens for all the 46 chromosomes in the embryo for any abnormalities in their numbers e.g Down’s Syndrome with additional Chromosome 21 or Turner’s Syndrome with absent chromosome X .
- PG-M ( M= Monogenic , previously known as PGD ) is to detect a specific disease in the embryo when there is a 25% – 50% chance to have a child affected with a specific genetic disease e.g Thalassemia . PGT-M can identify which embryo(s)are affected, unaffected, or a carrier (if applicable) for that disease before we transfer the embryo into the uterus for a pregnancy.
- PGT-SR( SR = Structural rearrangement ) can identify which embryos have an abnormal amount of chromosomal material in cases such as translocation or deletion of a segment of chromosome which can result in unbalanced amount of genetic material resulting in recurrent miscarriages .