At a glance
Learn what embryo mosaicism means in PGT-A results, how it is interpreted, and what options are available in Thailand, including questions to ask your clinic.
What Is Embryo Mosaicism in PGT-A?
When you undergo preimplantation genetic testing for aneuploidy (PGT-A), embryos are screened for chromosomal abnormalities. A result may come back as “mosaic,” meaning the embryo contains a mixture of cells: some with the expected number of chromosomes (euploid) and some with an abnormal number (aneuploid). Mosaicism is reported as a percentage, such as 20% or 50%, indicating the proportion of abnormal cells detected in the biopsy sample.
It is important to understand that mosaicism is a laboratory finding, not a diagnosis of a child’s health. The actual impact on a pregnancy depends on many factors, including which chromosomes are involved, the percentage of abnormal cells, and how the embryo develops. In Thailand, as elsewhere, PGT-A results are interpreted with caution, and mosaicism is not automatically considered a disqualifying factor for transfer.
At a Glance: Key Points About Mosaic Embryos
- Mosaic embryos have both normal and abnormal cells.
- Mosaicism is reported as a percentage, but the clinical significance varies.
- Some mosaic embryos may lead to healthy pregnancies, but outcomes are not guaranteed.
- Thai clinics have individual policies regarding mosaic embryo transfer.
- Genetic counseling is recommended to understand your specific results.
How Thai Clinics Interpret Mosaic Results
In Thailand, IVF clinics follow international guidelines for PGT-A, but there is no uniform national policy on mosaic embryos. Each clinic may have its own criteria for classifying mosaicism (e.g., low vs. high percentage) and for deciding whether to recommend transfer. Some clinics may prioritize euploid embryos and only consider mosaic embryos if no euploid embryos are available. Others may offer transfer of mosaic embryos after thorough counseling.
Because policies vary, it is essential to ask your clinic directly about their approach. You should also inquire about the laboratory’s reporting methods, as different technologies (such as next-generation sequencing) may have different thresholds for detecting mosaicism.
Options for Mosaic Embryos in Thailand
If you receive a mosaic PGT-A result, your options may include:
- Transfer of the mosaic embryo: Some clinics may offer this, especially if the mosaicism is low-level and the embryo is otherwise viable. You will need to discuss the potential risks and benefits.
- Further testing: In some cases, additional testing of the embryo may be possible, but this is not always available or conclusive.
- Preferring a euploid embryo: If you have other embryos that are euploid, your clinic may recommend transferring those first.
- Genetic counseling: A counselor can help you understand the specific implications of your results and guide your decision.
It is important to note that the decision to transfer a mosaic embryo is made on a case-by-case basis, considering your medical history, the embryo’s quality, and your personal preferences.
Questions to Ask Your Thai Clinic About Mosaic Embryos
Before making any decisions, consider asking your clinic the following questions:
- How does your laboratory classify mosaicism (e.g., low vs. high percentage)?
- What is your policy on transferring mosaic embryos?
- Are there any chromosomes that you consider more or less concerning in mosaic results?
- What is the recommended follow-up testing during pregnancy if I transfer a mosaic embryo?
- Do you offer genetic counseling as part of the process?
Next Steps: Making an Informed Decision
Receiving a mosaic result can be confusing, but you are not alone. Here is a step-by-step approach to help you move forward:
- Request a detailed explanation of your PGT-A report from your clinic.
- Ask about the specific percentage and chromosomes involved.
- Seek genetic counseling to understand the potential outcomes.
- Discuss your options with your fertility specialist, including the possibility of transferring the mosaic embryo.
- Consider your personal circumstances, such as the number of other embryos available and your age.
- Make a decision that aligns with your values and medical advice.
Remember, no embryo transfer can guarantee a pregnancy or a healthy child. The goal is to make the most informed choice possible with the support of your medical team.
Learn More About PGT in Thailand
For more information on preimplantation genetic testing, including PGT-A, PGT-M, and PGT-SR, visit our PGT in Thailand guide. You can also explore our other guides or check our FAQ for common questions.
Frequently asked questions
What does a mosaic PGT-A result mean?
A mosaic result means that the embryo has a mixture of cells with normal and abnormal chromosomes. It is reported as a percentage, but the clinical significance depends on many factors, including which chromosomes are affected and the percentage of abnormal cells.
Can I transfer a mosaic embryo in Thailand?
Some Thai clinics may offer transfer of mosaic embryos, but policies vary. It is important to discuss your specific results with your clinic and understand their criteria for considering mosaic embryos for transfer.
Are mosaic embryos safe?
Mosaic embryos may lead to healthy pregnancies, but outcomes are not guaranteed. The risk of an abnormal pregnancy depends on the specific chromosomal abnormality and the percentage of mosaicism. Genetic counseling can help you understand the potential risks.
What is the difference between a mosaic and an aneuploid embryo?
An aneuploid embryo has an abnormal number of chromosomes in all cells tested, while a mosaic embryo has a mixture of normal and abnormal cells. Mosaic embryos may have a higher chance of developing normally than fully aneuploid embryos, but this is not always the case.
Should I do additional testing if I have a mosaic embryo?
Additional testing may be possible in some cases, but it is not always conclusive. Your clinic can advise whether further testing is recommended based on your specific situation.
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.
Need help turning research into a shortlist?
