What it is, how it works, and what intended parents should know.

Preimplantation Genetic Testing (PGT) has transformed the fertility landscape, giving intended parents more insight into their embryos’ genetic health than ever before. While most people are familiar with tests like PGT-A (which screens for chromosome abnormalities) or PGT-M (which looks for single-gene disorders), a newer and more advanced option—PGT-P—is generating a lot of questions.

Below, we break down what PGT-P is, how it works, and how it differs from other types of PGT.

PGT-P stands for Preimplantation Genetic Testing for Polygenic Risk. It is an advanced genetic screening test for embryos that analyzes an embryo’s polygenic risk score (PRS) for common adult-onset diseases like certain cancers and cardiovascular disease. It is a probabilistic test, meaning it estimates a risk level, and is different from older PGT types that focus on single gene mutations or chromosomal abnormalities. 

How PGT-P Works

• Calculates a risk score: A PRS is calculated for the embryo for various conditions based on its genetic makeup.
• Uses a large genetic dataset: The analysis looks at many genetic variants and compares them to large populations to estimate the risk.
• Provides probabilistic results: The score is not a guarantee of getting or avoiding a disease, but rather an estimate of the embryo’s risk compared to the general population.
• Supplements other PGT tests: PGT-P can be used with other PGT tests, like PGT-A (aneuploidy) and PGT-M (monogenic disorders), to provide more comprehensive information about the embryo. 

Key Differences from other PGT

• Focus: PGT-P focuses on polygenic conditions (influenced by many genes and environmental factors), whereas PGT-M focuses on single-gene disorders.
• Result type: PGT-P provides a probabilistic risk score, while PGT-M can definitively identify if an embryo is impacted, unaffected, or a carrier for a specific disease.
• Complexity: It is a more complex test because it considers a broader spectrum of disease risk rather than a single, simple genetic issue. 

Considerations and Limitations

• Environmental factors: PGT-P does not account for non-genetic factors like lifestyle, which can significantly influence the actual risk of developing a disease.
• Ethical questions: It raises ethical considerations regarding embryo selection, the potential for “designer babies,” and equal access to the technology.
• Regulatory status: The technology is still developing, and regulatory guidelines and scientific evidence are still evolving in many places. For example, it is currently not permitted in the UK. 

It’s important to remember: polygenic risk is just one piece of the puzzle. Environmental factors, lifestyle, and family history also play major roles.

Who Might Consider PGT-P?

PGT-P may be helpful for:

• Intended parents undergoing IVF who want additional genetic insight
• Individuals or couples with strong family histories of common diseases
• Patients already doing PGT-A or PGT-M who want a more comprehensive picture

It is always recommended to discuss PGT-P with a genetic counselor, who can explain how the test applies to your medical history and family-building goals.

Is PGT-P Right for You?

PGT-P is not necessary for everyone, but it can offer added clarity for families seeking to reduce the risk of certain adult-onset conditions. As with all genetic testing, it’s important to weigh the benefits, limitations, and ethical considerations.

At Global Fertility & Genetics, we provide personalized guidance to help intended parents make informed decisions. Our team is here to walk you through every step—from IVF to genetic counseling to understanding your results.If you’re considering PGT-P or want to learn more about your options, contact our team today.