PGT-A

PGT-A is a form of embryo screening, used to test which of your embryos in an IVF cycle have the correct chromosomal arrangement, so that only normal chromosomal embryos are used, providing the best chance of a successful and healthy pregnancy. Cells from each embryo are removed in a safe biopsy process and used to examine the embryos’ chromosomes and genetic material.

Would you benefit from aneuploidy screening?

PGT-A is designed to examine an embryo’s genetic blueprint, which is concentrated into chromosomes. Normally, an embryo will inherit 23 chromosomes from the egg and 23 from the sperm, leading to 46 in total in each cell. Our testing takes a small sample of cells from each embryo and assesses for aneuploidy, which is when a cell has an unbalanced chromosomal structure, either due to extra or missing chromosomes.

Embryos with abnormal genetics — known as aneuploid embryos — unfortunately have a higher risk of failed uterine implantation or miscarriage, and are more likely in people who are older when trying to get pregnant. Pre-pregnancy genetic testing can give you a better chance at a successful pregnancy.

PGT-A may be a beneficial part of your fertility treatment if you:

have experienced recurrent miscarriage;
have had multiple unsuccessful IVF cycles;
have a family history of genetic disorders; or
are over 37 years old.

Unlike PGT-M which only assesses for specific genetic conditions inherited from the parents or evident in the family history, PGT-A is a broader screening process that looks at the overall genetics of an embryo to assess risk.

The embryo testing process

Genetic testing gives us more information about the health of your embryos when going through IVF, and helps us ensure a greater chance your baby will not develop any chromosomal conditions. Using PGT-A can provide some peace and assurance during fertility treatment.

Collection: Patients will undergo the typical process involved in ICSI, with eggs being retrieved and then fertilised with a single sperm sample in the hopes of creating multiple viable embryos. We keep a close watch on all embryos to ensure a healthy development.
Biopsy: Embryos that successfully grow to the blastocyst stage (typically around 5 days after fertilisation) have a few cells removed from their outer layer in a safe biopsy process. We use these cells to determine the number of chromosomes that the embryo has and whether it is likely to develop normal and healthy.
Implantation: Once results have returned, we implant an embryo that has no detectable chromosomal abnormality (aneuploidy). As part of the embryo transfer process in your IVF cycle, it will be implanted directly into the uterus in hopes of a successful pregnancy.

Any viable embryos that were not implanted will be safely frozen and stored in the case of future need. Once we have your results, we will organise an appointment to take you through them and discuss next steps.

Results

In some cases, PGT-A testing will not lead to a full result. This happens when the sample of cells we collect for the biopsy unfortunately does not represent the cells of the whole embryo. A condition called mosaicism may occur, which means that some cells have an abnormal number of chromosomes while others have a normal number. In this case, it is still possible to implant an embryo with a low level of mosaicism, but we will assess to see if there are more viable options.

There is a small risk of an incorrect biopsy result — around a 1 to 2% chance — so chromosomal testing during any resulting pregnancy is recommended.

PGT-A may also identify that all embryos have inherited an incorrect number of chromosomes and are not viable for transfer. This is an unlikely occurrence, and is typically less common in younger people, but it can mean that you are unable to have any embryos implanted. If this happens, we can help you understand why and how to move forward with other options and pathways.

The testing screens for the chromosomal makeup of embryos but not the individual genetic makeup of the embryo. Because of this, some children may still be born with abnormalities even if PGT-A screening suggested they would not. Unfortunately, the testing cannot give us absolute certainty, but it does represent the best test we have for assessing aneuploidy in embryos.

Alternative tests

We take great care to assess as many different factors that affect fertility as possible. With different genetic tests, fertility assessments and even general health checks, our team looks at every aspect to find your best path to pregnancy.

Genetic Carrier Screening Test

By testing your saliva or a blood sample in a simple procedure, we can screen for hundreds of potential genetic conditions and identify how likely you are to have a baby with different conditions. We’ll support you with clear information and a comforting hand as you plan your next steps.

Preimplantation Genetic Testing for Single Gene Conditions (PGT-M)

PGT-M is used to check whether there are any specific mutations in an embryo’s genetics, typically when there is a known condition that runs in the family of one or both parents. We can check whether that condition appears present in the embryo prior to implantation.

Fertility Health Check

To best understand your current fertility situation, we take a complete medical history from each patient, before getting a sense of your lifestyle, general health and how long you have been trying. We can assess your fertility health and help create the right program for you.

Egg Timer Test

Using a simple blood test, we can measure your level of anti-mullerian hormone (AMH), which tells us how many eggs you still have in your ovaries, known as your ‘ovarian reserve’. This helps us understand your level of fertility health relative to the average for your age.

FAQ

What is the difference between genetic testing and genetic screening?

The main difference is the time when the test is conducted. Genetic screening is typically conducted prior to falling pregnant (though it can be completed after), and is used to assess whether any prospective parents or donors are carriers of one or more genetic disorders. By contrast, genetic testing is used to assess whether any genetic conditions are present in an embryo. This can be done before pregnancy with PGT or during pregnancy with CVS (Chorionic villus sampling) or amniocentesis.

PGT-A vs PGT-M — what’s the difference?

While both involve genetic testing of embryos, they each assess for different things. PGT-A is used to assess whether an embryo has the correct chromosomal arrangement, with that information used to identify whether the embryo is at risk of a broad range of genetic conditions. PGT-M is comparatively used to assess for markers of a specific genetic disorder when one or more of the parents are known to be a carrier.

Your Path to a Healthier Pregnancy

If you’ve faced challenges like recurrent miscarriages, unsuccessful IVF cycles, or concerns about genetic conditions, PGT-A could provide the clarity and confidence you need on your fertility journey.

Our compassionate team is here to guide you through each step, from embryo collection to testing and implantation, ensuring you feel supported and informed throughout the process. If you think PGT-A may be right for you, book an appointment with one of our fertility specialists today.