At a glance
Understand the common PGT-A result categories—euploid, aneuploid, and mosaic—and what they may mean for your embryo transfer decisions, with practical questions to ask your clinic in Thailand.
If you have just received your PGT-A results from a clinic in Thailand, you may be looking at terms like “euploid,” “aneuploid,” and “mosaic.” These words describe the chromosomal status of your embryos, and they can influence your next steps. This guide explains these categories in plain English, what they might mean for your transfer decisions, and what to ask your clinic to feel more confident about your options.
At a glance: PGT-A result categories
- Euploid: The embryo has the expected number of chromosomes (46 in most cases).
- Aneuploid: The embryo has missing or extra chromosomes.
- Mosaic: The embryo has a mix of cells with normal and abnormal chromosomes.
- No result: The test did not produce a clear result, and you may need to discuss options with your clinic.
What is PGT-A?
Preimplantation Genetic Testing for Aneuploidy (PGT-A) is a test that checks embryos created through IVF for chromosomal abnormalities. It is not a test for specific genetic diseases—that is a different test called PGT-M. PGT-A looks at the number of chromosomes in the embryo’s cells. Having the correct number of chromosomes is important for an embryo to have the best chance of implanting and developing into a healthy baby.
In Thailand, PGT-A is offered by many fertility clinics as part of an IVF cycle. The test is performed on a small sample of cells taken from the embryo before transfer. The results can help you and your doctor decide which embryo to transfer first.
Understanding the three main results
Euploid
An embryo is called euploid when it has the expected number of chromosomes. For a typical human embryo, that means 46 chromosomes. Euploid embryos are generally considered to have the highest chance of implanting and developing into a healthy pregnancy. However, a euploid result does not guarantee a successful pregnancy or a healthy baby. Other factors, such as the embryo’s quality and the health of the uterus, also play a role.
Aneuploid
An embryo is called aneuploid when it has missing or extra chromosomes. For example, an embryo with three copies of chromosome 21 is aneuploid. Aneuploid embryos often fail to implant or may lead to miscarriage. If an aneuploid embryo does implant, it can result in a child with a chromosomal condition, such as Down syndrome. Most clinics do not recommend transferring an aneuploid embryo, but the decision is always made in consultation with your doctor.
Mosaic
A mosaic embryo has a mixture of cells: some with the normal number of chromosomes and some with an abnormal number. The degree of mosaicism can vary—some embryos have a low percentage of abnormal cells, while others have a high percentage. Mosaic embryos are a gray area in PGT-A. Some studies suggest that mosaic embryos can still lead to healthy pregnancies, but the risk of chromosomal abnormalities may be higher than with euploid embryos. Your clinic may offer additional counseling to help you understand the specific level of mosaicism and what it might mean for your situation.
What do PGT-A results mean for your transfer decision?
Your PGT-A results are one piece of information to consider when planning your embryo transfer. Here are some general points to keep in mind:
- Euploid embryos are usually prioritized for transfer because they have the highest chance of success.
- Aneuploid embryos are typically not transferred, but you should discuss the risks and alternatives with your doctor.
- Mosaic embryos may be considered for transfer if no euploid embryos are available, but this decision requires careful discussion about the potential risks and benefits.
It is important to remember that PGT-A is a screening test, not a guarantee. Even a euploid embryo may not result in a pregnancy. Your doctor will consider your age, medical history, and the quality of your embryos when making recommendations.
Questions to ask your clinic about your PGT-A results
When you receive your PGT-A report, you may have questions. Here are some questions you can ask your clinic to better understand your results:
- What is the exact chromosomal status of each embryo?
- For mosaic embryos, what is the percentage of abnormal cells, and which chromosomes are affected?
- What is the recommended transfer order for my embryos?
- Are there any additional tests or counseling you recommend?
- What are the risks and success rates associated with each type of embryo?
- How does my age and medical history affect the interpretation of these results?
Next steps after receiving your PGT-A results
After you receive your PGT-A results, you may need to make decisions about your next cycle. Here is a simple checklist to help you move forward:
- Review your results with your doctor and ask any questions you have.
- Discuss the transfer order and whether any additional testing is needed.
- Consider genetic counseling if you have questions about the implications of your results.
- Plan your next steps, whether that is preparing for a transfer or considering another IVF cycle.
- Take time to process the information—this is an emotional journey, and it is okay to ask for support.
Where to learn more
For more information about PGT in Thailand, you can explore our PGT in Thailand guide. You may also find our guides and FAQ pages helpful as you continue your journey.
Frequently asked questions
What does a euploid embryo mean?
A euploid embryo has the expected number of chromosomes (46 in most cases). It is generally considered to have the highest chance of implanting and developing into a healthy pregnancy, but it does not guarantee success.
Can a mosaic embryo be transferred?
In some cases, a mosaic embryo may be considered for transfer if no euploid embryos are available. The decision depends on the level of mosaicism and the specific chromosomes involved. You should discuss the risks and benefits with your doctor.
What is the difference between PGT-A and PGT-M?
PGT-A screens embryos for chromosomal abnormalities (aneuploidy), while PGT-M tests for specific genetic disorders. They are different tests and are used for different purposes.
Do PGT-A results guarantee a healthy baby?
No. PGT-A is a screening test that can reduce the risk of transferring an embryo with a chromosomal abnormality, but it does not guarantee a successful pregnancy or a healthy baby. Other factors also affect outcomes.
What should I do if my PGT-A result is 'no result'?
If your PGT-A result is inconclusive, your clinic may recommend repeating the test, or you may discuss other options. It is important to ask your doctor what the no-result finding means for your specific embryos.
Continue your research
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.
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