PGT for Advanced Maternal Age in Thailand: What It Can and Cannot Tell You

Preimplantation genetic testing (PGT) is a laboratory step that can be added to an IVF cycle to examine embryos before transfer. For patients over 35, the main reason PGT is discussed is that the chance of an embryo having the wrong number of chromosomes — called aneuploidy — tends to rise with age. PGT-A is the version most often raised in this context. It is not a guarantee of pregnancy or a healthy child, and it is not automatically right for everyone. In Thailand, as elsewhere, whether PGT is offered and which type is used depends on your history, your embryos and the clinic’s own protocols.

At a glance

• Age matters mainly for PGT-A, which looks at chromosome number. The likelihood of aneuploidy increases with maternal age, but age alone does not decide whether you should test.
• PGT-M and PGT-SR are different. They are used when there is a known inherited condition or a known structural chromosome rearrangement, not simply because of age.
• PGT is a screening or diagnostic tool, not a treatment. It cannot create healthy embryos or fix an embryo.
• Results can be uncertain. Some embryos give a “no result” or “mosaic” outcome, and clinics differ in how they handle these.
• Costs, legal rules and paperwork vary. Confirm all of these directly with the clinic and relevant authorities before you travel.

Why age is linked to PGT-A discussions

Eggs are formed before birth and age with the person. Over time, the machinery that separates chromosomes during cell division becomes less reliable, so an embryo created from an older egg is more likely to have an extra or missing chromosome. This is a biological tendency, not a personal failing, and it does not mean every embryo will be affected.

Because aneuploidy is more common with age, some clinics are more likely to discuss PGT-A with patients over 35, especially those with previous IVF cycles that did not lead to a live birth, or previous miscarriages. However, guidance from professional bodies does not recommend PGT-A for every patient based on age alone. It is usually a shared decision that weighs the possible benefits against the costs, the extra laboratory steps, and the possibility that no embryo will be available to transfer after testing.

What PGT-A, PGT-M and PGT-SR actually look at

These three tests are often grouped together, but they answer different questions.

Test	Main question	Typical reason it is discussed
PGT-A	Does this embryo have the expected number of chromosomes?	Age-related risk of aneuploidy, recurrent miscarriage, repeated unsuccessful transfers
PGT-M	Does this embryo carry a specific gene variant linked to a known condition?	A known inherited condition in the family or in one or both parents
PGT-SR	Does this embryo have an unbalanced form of a known chromosome rearrangement?	A known structural rearrangement such as a translocation in a parent

PGT-A is the type most connected to age. PGT-M and PGT-SR are usually considered because of a specific genetic finding, not because of age. A clinic may sometimes combine tests, but the reasons and the laboratory work are different.

How Thai clinics may frame PGT-A for patients over 35

Thailand has a well-developed IVF sector, and many clinics follow international laboratory standards. Even so, individual clinics set their own internal policies. When age is the main reason PGT-A is being discussed, you may hear some of the following framings. Treat them as conversation points, not as rules that apply everywhere.

• “We usually discuss PGT-A from a certain age.” Some clinics use an age threshold as a prompt for discussion, but the decision should still be individual.
• “Testing may help us choose which embryo to transfer first.” This is a common rationale, but it depends on how many embryos you have and whether any give a clear result.
• “Testing may reduce the chance of transferring an embryo with an abnormal chromosome number.” This is plausible, but it does not remove all risk, and it does not guarantee a pregnancy.
• “We may recommend not testing if you have very few embryos.” Some clinics raise this because testing a small number of embryos can leave nothing to transfer.
• “We may offer a fresh or frozen transfer plan.” PGT usually requires embryos to be biopsied and then frozen while results are awaited, but protocols vary.

Because these are clinic-level practices, ask directly how the clinic decides, what its laboratory does, and what happens if results are unclear.

What a PGT result can and cannot tell you

A PGT result is information about the cells that were sampled, not a complete picture of the embryo or the future child.

• Euploid: the expected number of chromosomes was seen in the sampled cells. This does not guarantee implantation, pregnancy or a healthy baby.
• Aneuploid: an abnormal chromosome number was seen. This usually means the embryo is not recommended for transfer, but the clinic will explain what it found.
• Mosaic: a mix of normal and abnormal cells was seen. Some clinics may consider transferring certain mosaic embryos after counselling; others may not. This is a clinic-specific and case-specific decision.
• No result or inconclusive: the test could not give a clear answer. The clinic may offer re-biopsy, repeat testing or a different plan.

PGT-A does not test for every possible genetic condition. It does not measure embryo quality in general. It does not predict intelligence, appearance or future health beyond the chromosomes examined. PGT-M and PGT-SR are more targeted, and their meaning depends on the specific condition or rearrangement being tested.

Possible alternatives and additions to PGT

PGT is one option among several. Depending on your situation, you and your clinician might also discuss:

• IVF without PGT, with embryo selection based on standard laboratory grading.
• Expectant management or further natural attempts, if that is medically appropriate for you.
• Donor eggs, which changes the age-related chromosome risk profile because the eggs come from a younger donor. This is a significant decision with its own legal, ethical and emotional considerations.
• Genetic counselling, especially if there is a known inherited condition or a history of recurrent miscarriage.
• Additional testing during pregnancy, such as screening or diagnostic tests, which are separate from PGT.

None of these is universally better. The right path depends on your medical history, your values and what is available to you.

Practical questions to ask a clinic in Thailand

Bring these questions to your consultation. Write down the answers so you can compare clinics fairly.

1. Based on my age and history, why are you recommending or not recommending PGT-A?
2. Which PGT type are you proposing, and what exactly will it test for?
3. What proportion of embryos typically give a clear result in your laboratory, and what happens if mine do not?
4. How do you handle mosaic results? Do you transfer them, and under what conditions?
5. What are the total costs, including biopsy, testing, freezing, storage and any re-testing?
6. What are the legal and consent requirements for international patients using PGT in Thailand?
7. What documents do I need to bring, and how long should I plan to stay?
8. Who will explain the results to me, and in what language?
9. What are my options if no embryos are suitable for transfer after testing?
10. Can I speak with a genetic counsellor if needed?

Planning checklist for international patients

• Gather your medical records, including previous IVF cycles, miscarriage history and any genetic test results.
• Ask the clinic for a written summary of its PGT approach, costs and consent process.
• Confirm visa, travel and accommodation requirements with the relevant authorities and the clinic; rules can change.
• Ask how results will be communicated and what follow-up is included.
• Consider independent genetic counselling before you decide, especially for PGT-M or PGT-SR.
• Plan for uncertainty: testing may reduce the number of embryos available for transfer.

Where to read more

For a broader overview of PGT in Thailand, see our PGT in Thailand guide. Our patient guides cover related planning topics, and the FAQ section answers common questions about testing, travel and clinic communication.

Frequently asked questions

Does every IVF patient over 35 need PGT-A in Thailand?

No. Age increases the chance of aneuploidy, but professional guidance does not recommend PGT-A for everyone based on age alone. Whether it is offered depends on your history, the number of embryos you have, and the clinic's protocols. It is usually a shared decision after discussing benefits, costs and limitations.

What is the difference between PGT-A, PGT-M and PGT-SR?

PGT-A looks at the number of chromosomes and is the type most often discussed in relation to age. PGT-M looks for a specific inherited condition, and PGT-SR looks for a known structural chromosome rearrangement. PGT-M and PGT-SR are usually considered because of a known genetic finding, not because of age.

Can PGT guarantee a healthy baby?

No. PGT can provide information about the cells sampled from an embryo, but it cannot guarantee implantation, pregnancy, live birth or a child without any health condition. It does not test for every possible genetic or health issue, and some results are uncertain.

What happens if my PGT result is mosaic or inconclusive?

A mosaic result means a mix of normal and abnormal cells was seen, and an inconclusive result means the test could not give a clear answer. Clinics differ in how they handle these situations. Some may consider transferring certain mosaic embryos after counselling, while others may not. Ask your clinic about its specific policy before you start.

How should I compare clinics in Thailand for PGT?

Ask each clinic the same questions: why it recommends or does not recommend PGT for your situation, what the total costs include, how it handles unclear results, what legal and consent steps apply to international patients, and how results will be explained. Compare the answers in writing rather than relying on general impressions.

Continue your research

• PGT in Thailand overview
• PGT and IVF guides
• Frequently asked questions

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.