If you’re on your IVF journey, you might have heard of preimplantation genetic testing, or PGT.
The concept might scare you, or maybe you don’t have enough information to consider it as an option. Although you may be aware of what the test does, how do you decide whether PGT is particularly right for you?
This article lays out the basic decision factors, so you can make an informed choice about whether to include PGT in your IVF journey.
What is preimplantation genetic testing?
Preimplantation genetic testing (PGT), previously called PGS or PGD (preimplantation genetic screening/diagnosis), is a test used to assess the chromosomal makeup of an embryo, or to identify genetic abnormalities in embryos produced through IVF, prior to embryo transfer.
PGT identifies potential genetic abnormalities that can result in failed implantation, miscarriage, birth defects, or debilitating disease in your child.
There are three types of preimplantation genetic testing: PGT-A, PGT-M and PGT-SR. You can ask your doctor for more information about the different types, or read more here.
Why is preimplantation genetic testing useful?
There are multiple reasons patients choose to do preimplantation genetic testing.
Reduce risk of IVF failure and miscarriage
Abnormal embryo genetics is one of the most common reasons embryo transfers do not result in pregnancy. Furthermore, over 50% of miscarriages are caused by abnormal chromosomal conditions.
Although women in their 40s have a more than 30% chance of trisomy (i.e. embryos have one additional chromosome), they have a greater risk of implantation failure and miscarriage.
PGT ensures that the embryos transferred have the right number of chromosomes, thus reducing the likelihood of IVF failure as well as miscarriage.
Reduce risk of twins or more
PGT determines the healthiest embryos for implantation. As such, this often enables the doctor to transfer only one embryo, significantly lowering the chance of having multiples.
Learn the sex of the embryo
As well, the test also reveals the sex of an embryo. Although this is a controversial decision factor, for some future parents it is a consideration worth mentioning.
Who should consider preimplantation genetic testing?
Preimplantation genetic testing is not necessary for everyone. However, if you find yourself in one or more of these categories, it may be something to consider:
- Women over 37 (due to increased risk of genetic abnormalities in embryos)
- Recurrent miscarriages
- Recurrent implantation failure from previously untested embryos
- Couples carrying dominant or recessive genes for known inherited disorders
- Patients with unexplained infertility
- Couples wanting to test previously frozen embryos for future transfer success
How much does preimplantation genetic testing cost?
As PGT is not normally covered by insurance, it can quickly become expensive. The cost will depend on the genetics lab, your IVF fertility clinic, and the number of embryos you test.
On average, PGT costs $1,500 – $2000 for the embryo biopsy, plus $150 – $350 for each embryo tested. To cut costs: if you plan to test embryos from multiple retrievals, you can ask to batch the biopsies for a single round of testing at the PGT lab.
Is it worth the investment? That depends on who you are.
A UofT cost-effectiveness analysis of PGT with IVF found that, in most cases, PGT was more expensive and less effective than IVF alone. However, for older women with a high number of blastocysts, PGT might be cheaper and more effective.
A similar study by RMA New Jersey found that for patients with more than one embryo, augmenting IVF with PGT reduces healthcare costs, treatment time, and the risk of failed embryo transfer and clinical miscarriage, as compared to IVF alone.
What are the risks?
PGT is not a high-risk test in general. However, in handling and biopsying embryos, a small percentage of them could become damaged and thus unavailable for transfer. As well, it’s important to note that the test will never be 100% accurate.
How to decide?
There’s no simple answer. Your decision will probably depend on many factors, including benefits, risks, costs, and your personal values and situation.
If you have very few embryos, you may want to transfer right away. Alternatively, it may be more important for you to check for an abnormal hereditary gene first.
Perhaps you’re a woman over 40; due to the higher risk of having abnormal embryos, it generally makes more sense to test your embryos before transfer.
Only you can know what’s best for you and your family. Dr. Tanya Williams Fertility Centre is here to provide you with the right information and support to help you make that decision.
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