Receiving your PGT-A report can feel overwhelming. It is full of medical terms and abbreviations that are not part of everyday language. This guide explains the most common terms you will see on a PGT-A report from a clinic in Thailand, in plain English. It is not medical advice, and it does not replace a detailed discussion with your doctor. Instead, it helps you understand the basics so you can ask informed questions.
At a glance: key terms on your PGT-A report
- Euploid – the expected number of chromosomes (usually 46).
- Aneuploid – missing or extra chromosomes.
- Mosaic – a mix of cells with different chromosome numbers.
- No result – the test did not produce a clear answer.
What is PGT-A?
PGT-A stands for preimplantation genetic testing for aneuploidy. It is a test that can be done on embryos created through IVF before they are transferred to the uterus. The test looks at the number of chromosomes in the embryo. Humans typically have 46 chromosomes, arranged in 23 pairs. Having too many or too few chromosomes can affect whether an embryo develops normally or implants successfully.
PGT-A is not a guarantee of pregnancy or a healthy baby. It is one tool that may help you and your doctor choose which embryo to transfer. Not every patient needs PGT-A, and its usefulness depends on your individual situation.
Common terms and abbreviations
Euploid
Euploid means the embryo has the expected number of chromosomes. In a PGT-A report, this is often written as “euploid” or “normal.” A euploid embryo has the best chance of implanting and developing, but it is not a guarantee of a successful pregnancy or a healthy child.
Aneuploid
Aneuploid means the embryo has missing or extra chromosomes. This is often written as “aneuploid” or “abnormal.” Aneuploid embryos usually do not implant, or they may miscarry. Some aneuploid conditions, like trisomy 21 (Down syndrome), can result in a live birth with health challenges. Your doctor can explain the specific aneuploidy found in your report.
Mosaic
Mosaic means the embryo has a mix of cells: some with the expected number of chromosomes and some with an abnormal number. This is written as “mosaic” or “mosaic aneuploid.” The percentage of abnormal cells may be reported, for example, “20% mosaic.” Mosaic embryos are a gray area. They may have a lower chance of success than euploid embryos, but they can still lead to a healthy birth. The decision to transfer a mosaic embryo is complex and should be made with your doctor.
No result
Sometimes the test does not produce a clear answer. This can happen if the biopsy sample was too small, the DNA did not amplify well, or the embryo was not suitable for testing. “No result” does not mean the embryo is abnormal. It simply means the test could not give a definitive answer. Your clinic may offer retesting or discuss other options.
Other abbreviations you might see
- PGT-M – preimplantation genetic testing for monogenic disorders (single-gene diseases).
- PGT-SR – preimplantation genetic testing for structural rearrangements (like translocations).
- CNV – copy number variation, a type of genetic change.
- SNP – single nucleotide polymorphism, a type of genetic marker.
These tests are different from PGT-A. Your report may include results from multiple tests if you had them done together.
How to read your report: a step-by-step approach
- Find the embryo identification. Each embryo is usually labeled with a number or code.
- Look for the chromosome result. This is often listed as “euploid,” “aneuploid,” “mosaic,” or “no result.”
- Check for specific chromosomes. If an aneuploidy is found, the report may list which chromosome is affected (for example, “trisomy 21”).
- Note the mosaic percentage. If the embryo is mosaic, the report may show the percentage of abnormal cells.
- Read any additional comments. Some reports include notes from the laboratory about the quality of the sample or the confidence of the result.
If anything is unclear, write down your questions and ask your clinic. They can explain what the results mean for your specific embryos.
What your report does not tell you
A PGT-A report does not tell you everything about an embryo. It does not guarantee that an embryo will implant, develop, or result in a healthy baby. It also does not screen for all genetic conditions. PGT-A only looks at the number of chromosomes, not the structure or specific genes. Other tests, like PGT-M, are needed for single-gene disorders.
Additionally, PGT-A cannot predict the future health of a child. Even a euploid embryo may have other issues that are not detected by this test.
Questions to ask your clinic
- What does this result mean for my chances of pregnancy?
- Are there any limitations to this test?
- Should I consider retesting a “no result” embryo?
- What are the options for mosaic embryos?
- How does this result affect my transfer plan?
Next steps after receiving your report
- Schedule a follow-up appointment with your doctor to discuss the results.
- Bring a list of questions to the appointment.
- Ask for a written explanation if needed.
- Consider genetic counseling if you have questions about specific results.
Remember, your PGT-A report is a piece of information, not a final verdict. Your doctor will help you interpret it in the context of your overall treatment.
For more information about PGT in Thailand, see our PGT in Thailand guide. You may also find our guides and FAQ sections helpful.
Frequently asked questions
What does euploid mean on a PGT-A report?
Euploid means the embryo has the expected number of chromosomes (usually 46). It is often called 'normal.' A euploid embryo has a good chance of implanting, but it is not a guarantee of pregnancy or a healthy baby.
What does aneuploid mean?
Aneuploid means the embryo has missing or extra chromosomes. This can affect implantation or lead to miscarriage. Some aneuploidies, like trisomy 21, can result in a live birth with health challenges. Your doctor can explain the specific finding.
What is a mosaic embryo?
A mosaic embryo has a mix of cells with different chromosome numbers. For example, some cells may be euploid and some aneuploid. The report may show a percentage of abnormal cells. Mosaic embryos have a lower chance of success than euploid embryos, but they can still lead to a healthy birth. The decision to transfer a mosaic embryo is complex.
What does 'no result' mean on a PGT-A report?
'No result' means the test could not produce a clear answer. This can happen if the sample was too small or the DNA did not amplify well. It does not mean the embryo is abnormal. Your clinic may offer retesting or discuss other options.
Is PGT-A the same as PGT-M?
No. PGT-A screens for aneuploidy (chromosome number). PGT-M tests for specific single-gene disorders. They are different tests with different purposes. Your report may include results from both if you had them done.
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Medical information notice: This article is educational and does not replace individual assessment, diagnosis, genetic counselling or treatment advice from a licensed clinician. Provider services, availability, fees and policies should be verified directly before booking.