Genetic Testing

The most common form of genetic screening is commonly referred to as 3 gene screening because it test for 3 specific conditions that could impact the health of your child. These are the three most common genetic conditions in the community.

• Cystic fibrosis
• Spinal muscular atrophy
• Fragile X syndrome

Additional genetic testing is available that screens for further genetic risks. Once learning more about your health history, Dr Knight will advise which level of testing is most appropriate for you, however expanded reproductive screening will identify 80% of your genetic conditions that could potentially affect your baby.

Who is carrier screening for?

Dr Knight recommends gene screening to all patients planning to become parents to identify any genetic risk factors from the outset. People at particular risk include those with a family history or who have a history of multiple miscarriage or consanguinity.

How does it work?

Commonly this testing can be completed with a saliva or blood sample. Results are usually received between 4 – 8 weeks. Dr Knight frequently refers her patients to a genetic service with genetic counseling if required.

What if I’m a carrier?

If you are found to be a carrier of a gene that could affect the health of your child, your reproductive partner will need testing. If you are both carries you may

• Be referred to a geneticist for further testing and evaluation.
• Require IVF technologies to prevent passing an unwanted condition onto your child.
• Consider accessing donor sperm, egg or embryos.

What Is Preimplantation Genetic Screening?

Preimplantation screening is a test that is carried out on an embryo within the laboratory and is performed by the most senior embryologists. This genetic assessment aims to determine which, if any, embryos are carrying abnormalities to prevent returning any atypical embryos to the uterus.

There are various forms of preimplantation genetic screening:

• Preimplantation Genetic Diagnosis (PGD) – also known as single gene testing, this test assesses an embryo for disease caused by a single mutant such as sickle cell disease or Huntington’s disease.
• Preimplantation Genetic Testing (PGT), which includes:
  • PGT-A (Aneuploidy): Assesses embryos for chromosomal abnormalities such as additional or missing chromosomes, translocations or rearrangement of chromosome conditions such as down syndrome.
  • PGT-M (Monogenic Disorders): Assesses embryos for specific genetic disorders when one or both partners are known carriers such as cystic fibrosis, fragile x syndrome or BRCA genes.
  • PGT-SR (Structural Rearrangements): Screening for chromosomal structural issues that could lead to recurrent miscarriage or impact a child’s health.
    

Who is preimplantation screening for?

Dr Knight often recommends genetic screening for couples with a family history of genetic disorders, recurrent miscarriages, or unexplained infertility, as it can provide valuable information for their family planning. However not all couples undergoing IVF require preimplantation screening of their embryos. There are many factors Dr Knight considers when advising if a form of genetic screening will be beneficial including:

• The opinion of a geneticist.
• Consistent failed implantation of the embryo or recurrent miscarriage where chromosomal abnormalities may be a contributing factor.
• Previous pregnancy or birth affected by a chromosomal abnormality.
• Known chromosomal structural rearrangement, such as translocation
• If one or both parents are known carriers of a single gene disorder.
• Advancing age for both or either partner.
  

How does it work?

An IVF cycle is carried out in the usual way to create embryos that reach the blastocyst or day 5 stage, even up to day 6 post fertilization. A senior embryologist delicately performs a biopsy, collecting a small amount of cells from the outer wall of each embryo. These cells are carefully preserved and transported to the genetics team to undering the appropriate testing. Once the biopsy has been completed, the embryos are cryopreserved or frozen for later use if the genetic test is reassuring. Once your report has been received 4 – 6 weeks later, Dr Knight or her senior embryologist will call you to discuss your results and plan your next steps.

Do biopsies damage the embryos?

To provide the highest level of care, the biopsy procedure is completed by our highest qualified and experienced embryologist. We select the highest quality embryos to biopsy at the blastocyst stage to prevent any harm to the embryo. Our practices are in line with the most current research and laboratory standards and the genetics laboratory we use has registered accreditation and check to ensure the highest standard of care.

It’s important to be aware of the limitations and ethical considerations associated with genetic screening:

• Genetic testing is not an absolute guarantee for a healthy pregnancy or child and not 100% accurate.
• The process may bring up complex ethical questions, and some patients benefit from genetic counseling to understand and navigate these.

Support

We have highly experienced fertility counsellors within our team who can support you throughout your treatment. Dr Knight can refer you to a genetic specialist for further genetic counselling to discuss your options and help you make an informed and empowered decision.

What are the costs involved, and are they covered by Medicare?

Costs vary depending on the specific types of genetic tests needed. Medicare and insurance plans sometimes offer partial coverage, so it’s helpful to discuss options with your provider to understand the potential financial commitment.

To learn more about genetic screening options or to schedule a consultation, please reach out to our clinic. Our team is here to answer questions and provide additional support as you consider the best path forward for your family planning.