Pre-implantation Genetic Testing (PGT)

Pre-implantation Genetic Testing (PGT) is a specialised laboratory procedure performed alongside IVF treatment. PGT allows embryos created during IVF to be tested for certain genetic or chromosomal conditions before transfer to the uterus. The goal is to help identify embryos that may have the best chance of resulting in a healthy ongoing pregnancy. PGT does not improve the quality of embryos or guarantee pregnancy. Instead, it provides additional information that may help guide embryo selection. It does not improve overall success rates. PGT is usually performed when embryos reach the blastocyst stage, around day 5 or 6 of development. A small number of cells are carefully removed from the outer layer of the embryo (called a biopsy) and sent to a specialised genetics laboratory for analysis. The embryos are then frozen while results are processed. If a suitable embryo is identified, treatment continues with a Frozen Embryo Transfer (FET).

When you hear the words genetic testing, it can be easy to assume that all genetic tests are the same. They’re not.

Reproductive genetic carrier screening is usually performed using a blood or saliva sample from one or both reproductive partners. It can identify whether you or your reproductive partner carry certain genetic variants and therefore whether there may be an increased chance of having a child affected by a particular inherited condition. If a significant genetic risk is identified, your fertility specialist may discuss further genetic assessment and reproductive options.

Your fertility specialist may discuss PGT if you have:

• Recurrent miscarriage
• Recurrent implantation failure
• A history of chromosomal abnormalities in pregnancy
• A known inherited genetic condition in your family
• A known chromosome rearrangement such as a translocation
• Advanced maternal age
• Previous/multiple unsuccessful IVF cycles
• A risk of passing on a serious genetic condition

For some people, PGT can provide reassurance. For others, it may help reduce the likelihood of transferring an embryo affected by a serious genetic or chromosomal condition.

Pre-implantation Genetic Testing for Aneuploidy 

PGT-A screens embryos for extra or missing chromosomes. This is the most commonly performed form of PGT and may be recommended for:

• Recurrent miscarriage
• Repeated failed IVF cycles

PGT-A aims to identify embryos more likely to result in an ongoing pregnancy, although it does not guarantee success and there is a small chance of damage to the embryo or a misleading result.

Pre-implantation Genetic Testing for Monogenic Disorders

PGT-M is used when there is a known inherited single-gene condition in a family. Examples may include:

• Cystic Fibrosis
• Huntington’s Disease
• Sickle Cell Disease
• Haemophilia

This process requires extensive preparation and may involve testing samples from other family members. Preparation can take several months before IVF treatment begins. Depending on your circumstances, you may also be referred to a clinical geneticist or genetic counsellor to further discuss the inherited condition, testing process, reproductive options, and implications for your family.

Pre-implantation Genetic Testing for Structural Rearrangements 

PGT-SR may be recommended when one partner carries a chromosome rearrangement such as a translocation or inversion.  Although a person may be healthy themselves, these rearrangements can increase the risk of:

• Embryos with abnormal chromosomes
• Implantation failure
• Miscarriage
• Genetic conditions in offspring

During your pre-treatment phase, you will meet with a Stellar Fertility embryologist for an education session.

The technique of PGT is introduced at the laboratory phase of your cycle following fertilisation.

Science phase

• Embryos are cultured in the laboratory until the blastocyst stage (day 5–6)
• A small number of cells are removed from the outer layer of suitable embryos
• You will meet with your fertility specialist to review your results. If a suitable embryo is identified, treatment continues with a Frozen Embryo Transfer cycle.

Like with all IVF treatment success rates with PGT depend on many factors, including:

• Age
• Egg quality
• Sperm quality
• Underlying fertility diagnosis
• Number of embryos available
• Type of genetic condition being tested

Current evidence suggests that PGT-A may:

• Reduce the likelihood of transferring embryos with chromosomal abnormalities
• Reduce miscarriage risk in some patients

However, PGT does not guarantee pregnancy or live birth. Importantly, while PGT-A may improve embryo selection in some patients, research has not consistently shown improved cumulative live birth rates for IVF patients. This is why careful individual assessment is important.

Your Stellar fertility specialist will discuss whether PGT is likely to benefit your individual circumstances.

Although PGT can identify embryo sex as part of chromosome analysis, under Victorian law sex selection is only permitted for medical reasons. An application must be made to the Patient Review Panel for approval of embryo sex selection.

Out of pocket fees begin from $2,150. Medicare rebates are only available to cases where PGT-M is clinical required.

For further information on Stellar Fertility’s PGT fees, visit our fee page or call 03 9123 8200 to speak with one of our delightful team members.