Pre-implantation Genetic Testing (PGT)

PGT treatment aims to reduce the chance of passing a specific inherited disorder or a chromosomal abnormality to future children.


PGT is a form of testing carried out during IVF treatment. It is an additional step where the embryos created are biopsied and genetically tested to determine which, if any, of the embryos appear safe for transfer.

Our team carries out embryo biopsy for PGT-M, PGT-SR and PGT-A testing. Waterstone Clinic was the first clinic in Ireland to successfully deliver a baby following embryo biopsy for pre-implantation genetic testing.

Our PGT team will discuss your specific needs with you, and, together with the laboratory and genetic counsellor, will advise you about your specific case. It is essential to know that while PGT aims to reduce your chance of having a child with a specific genetic disorder, it does not test for all birth defects.

PGT-M: Preimplantation Genetic Testing for Monogenic/Single Gene Defects

If you are aware that you are a carrier of a particular genetic disorder or that a condition is present in your family, PGT-M testing can reduce the risk of your future child inheriting that particular condition.

Our team has carried out embryo biopsy to test for single-gene disorders including Cystic Fibrosis, Fragile X syndrome, Duchenne Muscular Dystrophy, Myotonic dystrophy, Tay- Sachs disease, Beta-thalassaemia, Haemophilia A, Sickle cell disease.

PGT-SR – Preimplantation Genetic Testing for Structural Rearrangements

If you know that you have a chromosomal rearrangement or have a child with a chromosomal rearrangement, such as a translocation or an inversion in the chromosomes, PGT-SR may be recommended. PGT-SR testing can reduce the risk of transferring embryos with missing or extra pieces of chromosomes, which can result in serious health issues for a child, and an increased risk of miscarriage.

PGT-SR may be recommended for patients who have a child or a pregnancy with a chromosome rearrangement or if they themselves are a carrier of an inversion, a reciprocal translocation or a Robertsonian translocation.

Preimplantation Genetic Testing for Aneuploidy

PGT can also evaluate an embryo’s chromosomes, the structures in every cell that contain our genes. It is not uncommon for embryos to have random chromosome abnormalities such as one too few or one too many chromosomes, also known as “aneuploidy”. Embryos with aneuploidy are more likely to result in a miscarriage or failed IVF cycle. Less commonly, aneuploidy may result in the birth of a child with a chromosome condition such as Down syndrome (trisomy 21).PGT-A testing screens embryos for the number of chromosomes they hold. PGT-A aims to avoid the risk of transferring aneuploid embryos and decrease both the risk of miscarriage and the chance of having a baby with a chromosomal anomaly.

PGT-A may be recommended to patients who have experienced recurrent and unexplained miscarriages, have had repeated unsuccessful IVF cycles, or are at risk of aneuploidy due to the age of the intending mother.

The PGT Treatment Process

The PGT treatment process involves the same steps as an IVF treatment cycle to create several embryos:

  • Following an egg collection, the eggs are fertilized with prepared sperm to create embryos.
  • These embryos are cultured and monitored for development.
  • After five days, embryos that appear to develop normally are deemed suitable for biopsy and genetic analysis.
  • A biopsy of the embryos takes place in our dedicated PGT laboratory at Waterstone Clinic
  • The biopsy cells are sent for genetic analysis to the specialist genetic testing laboratory in the UK
  • The embryo(s) that are diagnosed as unaffected with the specific condition or disorder may be selected for transfer or stored for future use

Patient Experiences of Pre-implantation Genetic Testing

Patients’ experiences of the process of PGT testing at Waterstone Clinic

Speak to our team