Pre-implantation Genetic Testing (PGT-M)

Waterstone Clinic first introduced Pre-implantation Genetic Testing (PGT-M, then called “pre-implantation genetic diagnosis”) in 2012. We achieved the first successful birth following PGT-M testing in Ireland. PGT-M is testing for couples or individuals who are at risk of or have a specific inherited condition. PGT-M is a laboratory technique following IVF/ICSI treatment that enables parents to reduce the risk of passing a known condition to their children.

Who is it for?

Genetic testing of embryos may be recommended where:

  • Parent(s) already have a child with a serious genetic condition
  • Parent(s) have a family history of a serious genetic condition or have the condition themselves
  • Parents have found out that they are both carriers for a condition

We carry out PGT-M testing for single-gene disorders such as:

  • Cystic Fibrosis
  • Fragile X syndrome
  • Duchenne Muscular Dystrophy
  • Myotonic dystrophy
  • Tay- Sachs disease
  • Beta-thalassaemia
  • Haemophilia A
  • Sickle cell disease

What does it involve?

The PGT-M process involves creating embryos through IVF/ICSI treatment. The embryos are then biopsied, and the genes of the embryos are genetically tested for the named condition. In simple terms, it is IVF/ICSI treatment with an extra testing step: 

  • Following egg collection, the eggs are fertilized with prepared sperm to create embryos.
  • These embryos are cultured and monitored for development.
  • After five days, embryos which appear to be developing normally are prepared and biopsied for the genetic analysis.
  • The embryos are cryopreserved and stored at Waterstone Clinic.
  • The biopsied cells are sent to a specialised genetic testing centre in the UK for testing. 
  • The embryo(s) are diagnosed as affected or unaffected by the genetic condition. The embryo(s) that are diagnosed as unaffected can be prepared for transfer into the womb, or remain in Waterstone Clinic for future use in a frozen embryo transfer cycle.

Important limitations of PGT-M

We recommend that patients who become pregnant from PGT-M have prenatal testing using CVS or amniocentesis. PGT-M is not a substitute for prenatal testing. Prenatal testing will reveal whether or not the PGT-M genetic testing analysis was correct and confirm whether or not the foetus has been affected by the specific genetic disease. Of those embryos diagnosed, PGT-M testing for a single gene disorder detects about 98/99% of affected embryos, but misdiagnoses can occur. 

The aim of PGT-M is to reduce the chance of your child being affected by a specific genetic disease, however, it does not test for all genetic diseases.

For further information about the PGT-M programme, our PGT team will be happy to answer your questions. 

Speak to our team