Preimplantation Genetic Testing: PGT-M / PGT-A / PGT-SR
An advanced technique to test embryos created via IVF to identify familial single gene disorders or chromosomal changes.
Introduction
Genea's PGT scientists have helped hundreds of families maximise the potential of having a baby. The first chromosome screening of embryos was launched in 1996, with testing for inherited single gene disorders introduced in 1998. Since then, our PGT techniques have continued to be world leading. Genea is one of the very few centres in Australia that has both IVF and genetics facilities onsite to perform these sophisticated tests successfully.
Genea’s own PGT assay tests embryos created via IVF to identify familial single gene disorders or chromosomal issues. By choosing embryos which have had genetic screening, you will increase the chances of a healthy ongoing pregnancy and birth of an unaffected child.
Preimplantation Genetic Testing for Aneuploidies (PGT-A)
Many embryos created either via natural conception or IVF are aneuploid regardless of your personal or family history.
Preimplantation genetic testing for aneuploidy (PGT-A) can identify whether an embryo has the standard number of chromosomes and gives you a way of reducing the risks of failed implantations, miscarriages and live births with genetic health issues and conditions such as Patau syndrome (Trisomy 13) and Edward syndrome (Trisomy 18). PGT-A identifies and excludes embryos with aneuploidy to maximise the chance of having a healthy baby.
PGT-A may be a suitable option in the following circumstances:
• A previous pregnancy has been affected by a chromosomal abnormality
• Maternal age is greater than 35 years old
• Recurrent miscarriages
• Repeated embryo transfers without pregnancy
Preimplantation Genetic Testing for Monogenic conditions (PGT-M)
PGT-M is a genetic test that can be performed in embryos created via in vitro fertilisation (IVF) when an individual or couple are known to have an increased chance of a specific single gene disorder. Once the embryos are at a suitable stage of development, a small number of cells are carefully extracted for analysis.
PGT-M allows you to reduce the chance of having a child affected with the single gene disorder that runs in your family. Genea PGT Scientists have experience in testing embryos for over 350 common and rare genetic conditions such as cystic fibrosis, thalassemia or Huntington disease.
The Genea Genetic team can provide advice based on your individual circumstances and have techniques which allow PGT to be an accurate testing option for most couples.
PGT-M may be appropriate in the following circumstances:
• An individual has a personal or family history of a confirmed genetic diagnosis where there is a risk of passing on a serious health issue to their children
• One or both reproductive partners are carriers of a single gene condition that may affect the health of a future child, such as spinal muscular atrophy and fragile X syndrome
PGT-M is not able to test an embryo for all known genetic conditions, such as when the underlying genetic basis is not known.
Pre-implantation Genetic Testing for Structural Rearrangements (PGT-SR)
Some individuals have the correct number of chromosomes just in a slightly different arrangement. This may be referred to as a balanced translocation or chromosomal inversion. People with balanced chromosomal rearrangements are healthy as they have the standard amount of genetic information. However, an individual with a balanced chromosomal rearrangement has a higher chance of passing on an unbalanced amount of chromosome information to their children. This can lead to miscarriage, or a pregnancy or birth of a child with issues with health and development.
Similar to PGT-A, PGT-SR is a technique where embryos are tested to identify whether they have the balanced, standard number of chromosomes. PGT-SR maximises the chance of healthy ongoing pregnancies for carriers of balanced chromosome rearrangements by identifying only chromosomally balanced embryos for transfer.
If you have been identified to have a chromosomal rearrangement, PGT-SR may be an appropriate option for you.
How to request testing
If you think you might PGT-M/PGT-SR might be appropriate for your situations, you should first discuss this with your Fertility Specialist who will assess your medical history and any relevant family history. If the specialist considers PGT-M/PGT-SR to be the right option for you, they will guide you through the necessary steps, which typically involves a referral to our Genea Genetics team.
For PGT-A, anyone can request this, but it is usually your Fertility Specialist who determines whether PGT-A is appropriate based on your medical history and reproductive needs and then refers you to the Genea pathology department for testing.
Enquire today
Questions about PGT? Speak to our Fertility Concierge team today.
FAQs
Preimplantation Genetic Testing (PGT) is an advanced technique used to test embryos created via IVF to identify genetic disorders or chromosomal abnormalities before implantation. PGT helps increase the chance of a healthy pregnancy by selecting embryos without known genetic issues.
Genea offers three types of PGT:
- PGT-A (Aneuploidy): Screens embryos for chromosome changes (such as missing or extra copies of chromosomes) that can cause chromosome conditions (e.g., Trisomy 21, which is the cause of Down syndrome.
- PGT-M (Monogenic conditions): Tests embryos for specific single-gene disorders.
- PGT-SR (Structural Rearrangements): Screens embryos for unbalanced chromosomes if a parent or donor carries achromosomal rearrangements.
PGT-A may be suitable if:
- You have experienced recurrent miscarriages or repeated failed embryo transfers.
- You are aged over 35.
- A previous pregnancy was found to have a chromosome change.
PGT-M can test embryos for known genetic conditions, including cystic fibrosis, thalassemia, Huntington’s disease, spinal muscular atrophy, and fragile X syndrome. It is suitable for couples with a known single-gene disorder in their family.
Genea’s GeneSure™ technology uses preimplantation genetic screening to detect chromosomal abnormalities to select the best possible embryo for transfer - as a result of the technology, at Genea, we have seen a 50% decrease in miscarriage rate* and double the live birth rates*
* Women using their own eggs at Genea's clinics excluding Perth, Newcastle and Christchurch Jan-Dec 2018.
No. PGT-M can only test for conditions with a known genetic cause and where there is a known increased risk for an individual couple of having a child with the condition based on their own genetic testing. Conditions where the underlying genetic basis is unknown cannot be tested.
PGT-SR is appropriate for individuals who carry balanced chromosomal rearrangements, such as translocations or inversions. While carriers are usually healthy, they have a higher risk of passing on unbalanced chromosomes, which can lead to miscarriage or genetic disorders in their children.
During IVF, embryos are cultured to a suitable stage of development. A few cells are carefully biopsied from each embryo and sent for genetic testing. Only embryos without chromosome changes or the genetic condition being tested for (if PGT-M) or are available for transfer.
- PGT-M / PGT-SR: You should first discuss with your Fertility Specialist, who will review your medical and family history. If appropriate, you will be referred to Genea Genetics for a consultation to discuss your testing options.
- PGT-A: Typically requested by your Fertility Specialist based on your reproductive history. Genea’s PGT scientists then perform the testing.
Yes. Genea has world-leading PGT techniques with both IVF and genetics facilities onsite, allowing precise and timely testing. Our scientists have decades of experience, helping hundreds of families achieve healthy pregnancies.
While PGT significantly reduces the risk of genetic/chromosome disorders and improves the chances of a successful pregnancy, it does not guarantee a healthy baby. Like any medical test, PGT can never be 100% accurate, but accuracy generally ranges from 90 - 99% depending on the type of test and your specific condition/test design. Furthermore, genetic knowledge is constantly evolving over time, meaning some genetic/chromosome conditions may not be known or detectable within our current knowledge and technology.
Costs vary depending on the type of PGT and the number of embryos tested. Your Patient Relationship Coordinator will provide a detailed estimate based on your individual needs.
Turnaround time depends on the test type and number of embryos. Generally, results are available within a few weeks, allowing your Fertility Specialist to plan embryo transfer accordingly. PGT-M requires a work-up (test design based on your individual genetic testing results), which can take up to 2-3 months. This may delay your first IVF cycle, but will not need to be repeated for future cycles.
