PGT-A vs PGT-M vs PGT-SR in Thailand: How to Understand the Differences

PGT-A, PGT-M and PGT-SR are three different types of preimplantation genetic testing used during IVF. They are not interchangeable. PGT-A looks at the number of chromosomes in an embryo. PGT-M looks for a specific inherited condition that runs in a family. PGT-SR looks at chromosome structure, usually when a parent carries a known rearrangement. Which one, if any, may be relevant depends on your history and is a clinical decision. This guide explains the differences in plain language and lists what to confirm with a clinic in Thailand.

At a glance

• PGT-A — checks chromosome number (for example, extra or missing chromosomes).
• PGT-M — checks for a specific gene variant or condition known to run in the family.
• PGT-SR — checks for chromosome structural rearrangements, such as translocations.
• All three require an IVF cycle and a biopsy of embryo cells.
• None of them guarantees a pregnancy, a live birth or a healthy child.
• Suitability is determined by a clinician, often with a genetic counsellor.

What PGT means in plain language

Preimplantation genetic testing (PGT) is a group of laboratory tests performed on embryos created through IVF, before any embryo is transferred to the uterus. A small number of cells is removed from the embryo (a biopsy), and those cells are tested in a laboratory. The results are used to help decide which embryo(s) might be considered for transfer.

PGT is not a treatment for infertility, and it does not improve the quality of an embryo. It is a screening or diagnostic tool that provides additional information. It also has limitations: it cannot detect every possible genetic or health issue, and it cannot guarantee an outcome.

The three main types of PGT testing in Thailand

Clinics in Thailand, like clinics elsewhere, generally group PGT into three categories. The names can be confusing because they sound similar, but each answers a different question.

PGT-A: chromosome number

PGT-A stands for preimplantation genetic testing for aneuploidy. Aneuploidy means an embryo has an abnormal number of chromosomes — for example, an extra copy or a missing copy of a particular chromosome. PGT-A is used to count chromosomes, not to read individual genes.

PGT-A may be discussed with patients in a range of situations, such as when there is a history of recurrent pregnancy loss, when the woman is older, or when previous IVF cycles have not led to a successful pregnancy. However, professional guidance varies, and PGT-A is not automatically recommended for everyone. Some clinics offer it routinely; others reserve it for specific situations. It is not a guarantee of a healthy pregnancy.

PGT-M: a specific inherited condition

PGT-M stands for preimplantation genetic testing for monogenic disorders. Monogenic means caused by a change in a single gene. PGT-M is used when a family is known to be at risk of passing on a specific inherited condition, such as cystic fibrosis, thalassaemia, spinal muscular atrophy, or certain other conditions.

Before PGT-M can be performed, the laboratory usually needs information about the specific gene variant in the family. This often involves a genetic test on the parents or an affected family member. PGT-M is therefore highly individualised: the test is built around one family’s specific variant. It is not a general screen for all genetic conditions.

PGT-SR: chromosome structure

PGT-SR stands for preimplantation genetic testing for structural rearrangements. Structural rearrangements are changes in the way chromosome material is arranged — for example, a translocation, where part of one chromosome is attached to another. A person can carry a balanced translocation and be healthy, but it can increase the chance of miscarriage or of a child being affected by an unbalanced chromosome arrangement.

PGT-SR is usually considered when a parent is known to carry a structural rearrangement, often identified after recurrent miscarriage or after a chromosome test. Like PGT-M, it is targeted to a known finding in the family.

PGT-A vs PGT-M vs PGT-SR: a comparison

Feature	PGT-A	PGT-M	PGT-SR
What it looks at	Number of chromosomes	A specific gene variant	Chromosome structure (rearrangements)
Typical reason it is discussed	Chromosome number concerns, history of loss, age-related risk	Known inherited condition in the family	Known structural rearrangement in a parent
Is it targeted to one family?	No — general chromosome count	Yes — built around a specific variant	Yes — built around a specific rearrangement
Does it require prior genetic information?	Usually not	Usually yes	Usually yes
Does it guarantee a healthy child?	No	No	No

This table is a general orientation only. A clinic will explain which test, if any, fits your situation.

Why a clinic might recommend one over another

The choice is not a matter of one test being “better” than another. Each test is designed for a different question. A clinic may recommend:

• PGT-A when the main concern is chromosome number, for example in the context of recurrent miscarriage or a previous aneuploid pregnancy.
• PGT-M when there is a known single-gene condition in the family and the specific variant has been identified.
• PGT-SR when a parent carries a known structural rearrangement, such as a translocation.

In some cases, more than one type of PGT may be relevant, or none may be recommended. The decision depends on medical history, genetic test results, the number and quality of embryos available, and the clinic’s laboratory capabilities. It is a clinical judgement, not a patient preference alone.

What PGT can and cannot tell you

PGT provides information about the cells that were biopsied. It cannot tell you everything about the embryo. Limitations include:

• It does not detect all genetic conditions.
• It does not guarantee implantation, pregnancy, live birth or a healthy child.
• It may produce results that are unclear or that require interpretation.
• It does not replace prenatal testing, which may still be offered during pregnancy.
• It adds cost and complexity to an IVF cycle.

Your clinic should explain the specific limitations of the test they are offering.

Alternatives and other options

PGT is one option among several. Depending on your situation, alternatives may include:

• IVF without PGT, with embryo selection based on standard laboratory criteria.
• Using donor gametes (sperm or eggs), if medically appropriate and legally available.
• Prenatal diagnosis during pregnancy, such as chorionic villus sampling or amniocentesis.
• Genetic counselling to understand risks and options without proceeding to PGT.

These options have their own benefits, risks and limitations. A clinician and a genetic counsellor can help you weigh them.

Questions to ask a clinic in Thailand

If you are considering PGT in Thailand, these questions can help you compare clinics and understand what is being offered:

• Which type of PGT are you recommending for my situation, and why?
• What information do you need from me or my family before the test can be performed?
• What are the limitations of this test in your laboratory?
• What happens if the result is unclear or inconclusive?
• What are the costs involved, and what do they include?
• What are the success rates for my age and diagnosis at your clinic?
• Do you provide genetic counselling, and is it included?
• What are the legal and regulatory requirements for PGT in Thailand for international patients?
• What documents do I need to bring, and what is the expected timeline?
• What alternatives do I have if I decide not to proceed with PGT?

Next steps

1. Gather your medical and genetic history, including any previous genetic test results.
2. Ask your current doctor for a referral or summary that you can share with a clinic in Thailand.
3. Contact one or more clinics and ask the questions above.
4. Request a consultation with a genetic counsellor if available.
5. Confirm costs, timeline, legal requirements and travel arrangements directly with the clinic.
6. Take time to consider the information before making a decision.

For more general information, see our PGT in Thailand page and our guides. You can also check our FAQ for common questions.

Frequently asked questions

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

PGT-A looks at the number of chromosomes in an embryo. PGT-M looks for a specific inherited condition caused by a single gene variant. PGT-SR looks at the structure of chromosomes, such as translocations. Each test answers a different question and is chosen based on your medical and family history.

Can I choose which PGT test I want?

PGT is a medical test, so the decision is made with a clinician. You can discuss your preferences, but the recommended test depends on your history, genetic findings and the clinic's assessment. In some cases, no PGT may be recommended.

Does PGT guarantee a healthy baby?

No. PGT can provide useful information, but it cannot guarantee a pregnancy, a live birth or a healthy child. It does not detect all genetic conditions, and it does not replace prenatal testing.

Is PGT available in Thailand for international patients?

Many clinics in Thailand offer PGT, but availability, legal requirements and eligibility can vary. You should confirm directly with the clinic you are considering, and check any current regulations with the relevant authorities.

What should I ask a clinic before deciding on PGT?

Ask which type of PGT they recommend and why, what information they need from you, the limitations of the test, what happens if results are unclear, the costs, and whether genetic counselling is included. Also ask about legal requirements and timelines for international patients.

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.