PGT-P testing: Can it support decision-making in IVF?

When certain conditions like heart disease, cancer, diabetes, and depression show up generation after generation, it’s natural to worry about what your child might inherit.

For concerned IVF patients, prioritizing their future family’s health often means looking for ways to reduce the risk of inherited conditions. The stakes are higher if you’re choosing between multiple embryos, all labeled “normal.”

PGT-P is one of the more recent additions to preimplantation genetic testing (PGT), designed to estimate genetic risk for complex, adult-onset conditions. It’s not a crystal ball into the future, but it does help patients make nuanced decisions at moments when every detail feels important.

In this article, we’ll explain what PGT-P testing is, how it works, and what benefits and risks to expect. We’ll also explore how you can make the most of embryo testing with advanced genetic optimization tools.

What is PGT-P?

Unlike PGT-A, which checks the number of chromosomes in an embryo, and PGT-M, which screens embryos for single-gene disorders, PGT-P — which stands for preimplantation genetic testing for polygenic risk — focuses on complex, multifactorial conditions.

Polygenic or multifactorial conditions include heart disease, certain cancers, and mental health conditions that are influenced by multiple genes, as well as environmental and lifestyle factors.

Instead of looking for that one big red flag in an embryo’s DNA, PGT-P looks at lots of small signals — tiny DNA variations scattered across the genome.

On their own, these differences might not mean much, but together, they can add up to a higher or lower estimated risk, called “polygenic risk” in clinical settings, for developing specific health conditions in a person’s lifecycle.

Source: Edward Jenner

To get a practical understanding of the PGT-P approach, let’s unpack:

1. What a polygenic risk score means

2. How the score helps with embryo evaluation

1. What is the polygenic risk score?

The polygenic risk score (PRS) is a way to determine how likely someone is to develop certain health conditions throughout their life based on their genetics.

Scientists create these scores using large-scale studies that analyse the DNA of thousands of people with or without certain conditions, like diabetes or breast cancer. Then, they identify tiny DNA patterns that are more defined in people who developed these conditions.

When your embryos’ DNA is analyzed, the lab checks for all known risk-related markers and tallies them to create a polygenic risk score.

Source: Cedric Fauntleroy

2. How are embryos scored and graded in PGT-P?

When you opt for PGT-P, each tested embryo is assigned a single number called the Embryo Health Score (EHS) based on the combined polygenic risk scores across multiple conditions. 

The result is a single score that ranks embryos from lower to higher lifetime genetic risk. Lower EHS indicates a higher cumulative risk of diseases across a range of conditions.

Note: EHS is only provided for euploid embryos — those with the correct number of chromosomes as determined by PGT-A.

What does PGT-P test for?

PGT-P offers a risk estimate and not a diagnostic test, so it can’t guarantee that your child will or won’t develop a particular condition.

Still, for some families, especially those with a strong family history of certain diseases, PGT-P can offer additional information to help choose between multiple embryos that otherwise seem equal.

Some of the conditions that PGT-P tests for include:

• Type 1 diabetes

• Type 2 diabetes

• Certain cancers, such as breast, prostate, testicular cancer, and basal cell carcinoma

• Coronary artery disease

• High blood pressure

• High cholesterol

• Mental health conditions, such as schizophrenia

💡 Tip

If you’re not sure what conditions run in your family, consider carrier screening with Nucleus before or during IVF. The platform offers whole-genome carrier screening with its Nucleus Family product — a simple, at-home DNA test that can analyze ~100% of your genes and assess your risk scores for over 2,000+ conditions, including rare inherited diseases, novel genetic variants, and mental health disorders. Order your kit to get started!

How accurate is PGT-P testing?

The expression of complex diseases is influenced by environmental and lifestyle factors, such as:

• Nutrition

• Physical activity

• Stress

• Access to healthcare

The good news is that research has shown that ranking embryos by EHS and choosing the one with the lowest combined disease risk can reduce the incidence of some conditions later in life. In sibling selection models, this approach shows relative risk reduction of up to 72%. 

Source: Edward Jenner

Clinical logistics: How does PGT-P work?

Like other embryo genetic testing options, PGT-P fits smoothly into your IVF timeline. 

Here’s what the clinical logistics look like:

1. IVF cycle starts: You’ll go through standard steps, including ovarian stimulation to produce eggs, egg retrieval, and fertilization in the lab to create embryos.

2. Parents’ saliva collection: You and your partner (or egg or sperm donor) provide a saliva sample early in the process. This gives the lab the genetic context that helps interpret the embryo’s DNA with greater accuracy later.

3. Embryo biopsy: Embryos are cultured for 5–7 days until they reach the blastocyst stage. At this point, there’s a distinct difference between cells that will become the placenta and the fetus. A few cells that will become the placenta are gently removed from each embryo, with no harm to the fetus.

4. Embryo freezing: After biopsy, embryos are frozen and safely stored until PGT-P testing results arrive and you choose an embryo for transfer.

5. Lab analysis: The genetics lab analyzes the embryo and parent samples to calculate polygenic risk scores for each condition included in the panel.

Once the lab receives the biopsy and saliva samples, it typically delivers the results within 14 days.

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How does PGT-P compare to other embryo testing options?

Once you start fertility treatment, your care team will suggest what (if any) PGT option you should get based on your particular situation.

The following table compares PGT-P to other preimplantation genetic tests:

The main difference between PGT-P and the other tests is that PGT-A, PGT-M, and PGT-SR screen for existing abnormalities in the embryo, while PGT-P predicts the likelihood of developing complex conditions later in life.

Bonus read — Learn more about embryo testing in the following guides:

• PGT-A vs. PGT-M

• What is PGS?

• PGS vs. PGD testing

• Pros and cons of genetic testing during IVF

• PGT-A testing success rate

Should you consider PGT-P testing?

You should meet with a genetic counselor, so you can go through your personal and family history and decide if PGT-P or another test works for you.

Source: Polina Tankilevitch

PGT-P testing can be particularly valuable if you:

• Have a family history of chronic or late-onset conditions, like breast cancer or Alzheimer’s disease, in your family

• Show high-risk scores in your own genetic or carrier screening

• Plan to do PGT-A and want to go one step further

• Expect many embryos in your IVF cycle

Tip: Looking for a reliable PGT-P testing option in the U.S.? LifeView by Genomic Prediction is one of the best providers of comprehensive PGT-P testing.

Benefits and drawbacks of PGT-P testing

PGT-P can give you some agency over your child’s health since it helps you choose the embryo with the highest Embryo Health Score and the lowest health risk.

Below is a summary of PGT-P benefits and drawbacks:

While PGT-P estimates relative risk for common conditions, it doesn’t fully capture the complexity of an embryo’s genetics. Many IVF patients struggle with decision-making — they see several viable embryos, and still don’t feel confident choosing.

That’s where advanced decision-support tools like Nucleus Embryo come in. It’s a software that offers a broader view of your embryos’ genetic makeup in a patient-friendly interface. The idea is to get deeper insights after the initial screening at the fertility clinic is complete, and facilitate empowered choices.

Nucleus Embryo: Give your child the best possible start in life

Nucleus Embryo is a sophisticated yet easy-to-use genetic software platform designed for parents. You can upload the data of up to 20 embryos on the platform, and uncover the complex genetic markers they carry. You automatically get a comprehensive view of each embryo’s future health and well-being — insights that traditional screenings don’t usually cover.

You can learn more with Nucleus Embryo, including predictions and common risk scores for dozens of conditions, such as:

• Heart health

• Neurological and mental health

  • Examples: ADHD, anxiety, depression, bipolar disorder, and more

• Rare hereditary conditions like cystic fibrosis and hemochromatosis

• General physical health

  • Examples: Chronic pain, rheumatoid arthritis, and osteoarthritis, asthma, restless leg syndrome, and seasonal allergies, among others

  • Conditions like endometriosis and PCOS in women

• Nutrition and metabolic conditions

  • Examples: Celiac disease and alcohol dependence

You can even get information beyond basic viability and learn about the embryos’ sex and other physical traits, such as predicted eye color, height, or severe acne.

Access all your embryo reports in an intuitive, interactive dashboard that lets you compare, sort, and filter your embryos side by side. There’s no confusing medical jargon or static PDFs — the findings are in plain language with supportive visual insights.

Is Nucleus Embryo credible?

Nucleus Embryo is backed by credible science and only relies on the latest advancements in genetic technology. It aims to complement medical guidance and respect the autonomy of prospective parents when it comes to reproductive decisions. The platform is HIPAA-compliant and upholds the highest standards of patient privacy.

Here’s how to get started:

1. Ask your clinic for PGT-P testing with LifeView by Genomic Prediction

2. Sign up for Nucleus Embryo during or after you complete your IVF cycle

3. Request your embryos’ PGT-P DNA data from your clinic

4. Upload the data to Nucleus Embryo and analyze the embryo analysis report

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Featured image source: Pavel Danilyuk