Pre-Implantation Genetic Testing (PGT)

Pre-Implantation Genetic Testing (PGT) is a revolutionary technology that has transformed the field of  reproductive medicine. A group of genetic tests evaluate embryos before transfer to the uterus. This  technology is used with in vitro fertilization (IVF) to increase the potential for a successful pregnancy  and delivery. 

What is PGT?

To analyze the embryos before transfer genetically. The primary goal of PGT is to identify genetic  defects within embryos before they are transferred into the uterus, preventing certain genetic  diseases or disorders from being passed on to the child.  

Types of PGT

There are three specific types of PGT: PGT-M (monogenic), PGT-A (aneuploidy), and PGT-SR (structural  rearrangements)  

• PGT-M is targeted to single gene disorders. It is used when a specific genetic disease needs to  be identified in the embryo. This may be desired to avoid passing on a genetic disease or to  choose a particular genetic tendency. (Source: New Hope Fertility) PGT-M testing offers many  benefits for patients who carry sex-linked genetic disorders, single gene and chromosomal  disorders, and patients over the age of 35.  
• PGT-A involves checking embryos for abnormalities in the number of chromosomes. Embryos  with missing or extra chromosomes, known as aneuploid embryos, have less chance of  developing into a baby. Or, less commonly, it may result in a baby being born with a genetic  condition. PGT-A gives information about embryo genetic health to help your care team select  the best embryo for transfer and improve your chances of achieving a successful pregnancy.  PGT-A can also be used by couples who wish to choose the sex of their intended child, also  known as gender selection (Source: CNY Fertility) 
• PGT-SR is a genetic test designed to detect inherited chromosomal rearrangements and  increase the chance of a successful pregnancy. This testing is commonly considered after  recurrent miscarriages or the birth of an offspring with chromosomal abnormalities, as  affected couples are generally healthy and unaware of the chromosomal structural  rearrangement that they carry. 

Benefits of PGT

The benefits of PGT are numerous. For one, it allows for selecting the healthiest embryos for  implantation, thereby increasing the chances of a successful pregnancy. It also reduces the risk of  having a child with a genetic disorder. For couples who have a history of genetic disorders or who are  carriers of a specific genetic mutation, PGT can provide reassurance and reduce anxiety associated  with passing on the condition to their child.  

Furthermore, PGT can help to reduce the risk of miscarriage, which is often associated with  chromosomal abnormalities. (Source: Illume Fertility) By screening out embryos, the likelihood of a  successful pregnancy is increased.

Limitations of PGT

Despite its benefits, PGT has limitations. False-positive and false-negative results are possible. Patients  and healthcare providers should be aware that a “normal” or negative PGT result is not a guarantee  of a newborn without genetic abnormalities. PGT is a powerful tool in the field of reproductive medicine, offering hope to couples struggling with infertility or genetic disorders. However, like all  medical procedures, it is not without its limitations and should be considered as part of a  comprehensive approach to fertility treatment.  

Sources:  

New Hope Fertility - PGT-A vs. PGT-M: What is the Difference? - New Hope Fertility Center

CNY Fertility - PGT-A: Preimplantation Genetic Testing for Aneuploidy | CNY Fertility 

Illume Fertility - Your Guide to Preimplantation Genetic Testing (PGT): Cost, FAQs & More  (illumefertility.com)