Pre-implantation Genetic Testing (PGT)

PGT-a is the most common form of embryo testing. It tests whether an embryo has the correct number of chromosomes. The correct number of chromosomes (46), also known as euploid, is necessary for the embryo to become a normal child. When an embryo’s cells have an incorrect number of chromosomes, either too few or too many, it’s known instead as aneuploidy. It can also tell you whether an embryo is male or female (XY or XX).

The prevalence of aneuploid embryos increases as women get older. Embryos with aneuploidy are more likely to result in an early miscarriage or failed IVF cycle, irrespective of the morphological appearance. Less commonly, aneuploidy embryos may result in the birth of a child with a chromosome condition, such as Down syndrome (trisomy 21).

In addition to Down syndrome, PGT-a can detect other full chromosome genetic abnormalities such as Turner’s syndrome (XO) and Klinefelter’s (XXY). PGT-a has been reported to have a high accuracy rate of about 98%.

A PGT-a normal embryo is estimated to have a 60% chance of live birth from a transfer cycle. 

PGT-M is used to confirm whether a specific inheritable condition is present within a patient’s embryos. It enables couples with an inheritable genetic condition in their family to avoid passing it on to their children. PGT-M is typically recommended in cases where one or both partners have a known history of genetic conditions in their families. Examples of some common single gene disorders that can be diagnosed with PGT-M include: Thalassemia, Haemophilia A and B, Fragile X syndrome, Sickle cell disease, Cystic fibrosis, Duchene muscular dystrophy, Huntingdon’s disease, and Marfan syndrome.