PGT (Preimplantation Genetic Testing): What You Need to Know

Preimplantation genetic testing (PGT) of embryos has made enormous strides since its introduction in 2005. Although genetic testing could be completed on human cells before 2005, techniques were created to perform genetic testing on just a few cells removed from a developing embryo.

Genetic testing allows prospective parent(s) undergoing in vitro fertilization (IVF) to test for a specific gene or chromosomal copy number abnormalities before the embryo transplant. This can increase pregnancy rates and decrease miscarriage rates.

PGT has become an integral part of Assisted Reproductive Technology (ART) procedures.

What is PGT (Preimplantation Genetic Testing)?

Preimplantation genetic testing (PGT – formerly known as preimplantation genetic screening and diagnosis, PGD and PGS) is defined by American Society for Reproductive Medicine (ASRM) as a technique in which one or more cells are taken from an egg or embryo (fertilized egg) for testing to provide information about the genetic make-up of the rest of the cells in that embryo. The procedure is completed in the IVF lab using in vitro fertilization (IVF).

Having an extra or missing chromosome(s), also known as aneuploidy, can result in a lack of implantation of an embryo, pregnancy loss, and children born with chromosomal abnormalities (i.e. Down syndrome, Turner syndrome, trisomy 13).

PGT for Aneuploidy Screening

Aneuploidy is an abnormal number of chromosomes in embryos, linked to the chronological aging of eggs.

Candidates for aneuploidy screening:

• Women 35 years or older
• Recurrent first-trimester pregnancy loss
• History of chromosomally abnormal pregnancy
• Previous in vitro fertilization (IVF) failure
• Family balancing of genders
• Improving the efficiency of IVF
• Reducing the number of embryos transferred = decreased risk of multiple gestations

PGT-M for Chromosomal Rearrangement

Candidates for chromosomal rearrangement include individuals who are known carriers of a chromosomal translocation or inversion.

PGT-M for Single Gene Disorder

Candidates for single gene disorder PGT-M include individuals who are known carriers of a specific genetic disorder (such as cystic fibrosis or Tay-Sachs), to identify embryos that are either an affected or carriers of the mutation.

Preimplantation genetic testing (PGT) can help detect the embryos that are most suitable for transfer during IVF to give you the best possibility of implantation and a successful pregnancy. Request an appointment today to learn more.