PGT-SR Testing in Thailand: What Patients With a Structural Rearrangement Should Know

PGT-SR is a type of preimplantation genetic testing used when one or both partners carry a known structural rearrangement, such as a translocation or inversion. It looks at chromosome structure in embryos created through IVF, rather than at a single gene. It is not a guarantee of pregnancy or a healthy child, and it is not the right test for everyone. Whether it is relevant depends on the specific rearrangement, the chromosomes involved, and advice from a genetics professional. This guide explains the general principles and the questions worth asking before planning treatment in Thailand.

At a glance

• PGT-SR is designed for people with a known structural rearrangement, not for general screening.
• It examines chromosome structure in embryos, while PGT-A looks at chromosome number and PGT-M looks at a specific gene.
• It cannot detect every possible genetic or health issue, and it does not guarantee an outcome.
• Results are usually reported as informative or non-informative, with details that a genetics professional can interpret.
• Availability, cost and laboratory arrangements vary by clinic and should be confirmed directly.

What PGT-SR is and what it is not

PGT-SR stands for preimplantation genetic testing for structural rearrangements. It is used when a person has a chromosome rearrangement that may affect how chromosomes are passed on to embryos. Examples include reciprocal translocations, Robertsonian translocations and inversions. These rearrangements can be balanced in the parent, meaning the parent is usually healthy, but they can lead to unbalanced chromosomes in an embryo.

PGT-SR is not a general fertility test. It does not screen for all genetic conditions, and it does not replace diagnostic testing during pregnancy if that is recommended. It is also not a treatment for infertility itself. It is a laboratory step that may be added to an IVF cycle to help select embryos for transfer based on chromosome structure.

How PGT-SR differs from PGT-A and PGT-M

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

Test	Main focus	Typical situation
PGT-A	Chromosome number (aneuploidy screening)	Used more broadly in IVF, often as a screening step, though its role is debated for some groups.
PGT-M	A specific gene or inherited condition	Used when a known single-gene disorder runs in the family.
PGT-SR	Chromosome structure	Used when a parent carries a known structural rearrangement.

In practice, a clinic may combine tests or use a customised approach. The choice depends on the exact rearrangement and the family history. A genetics professional can explain which test, if any, is appropriate.

Who might be offered PGT-SR

PGT-SR is generally considered when a structural rearrangement has already been identified, usually through karyotyping or another genetic test. It may be discussed in situations such as:

• A known balanced translocation in one partner.
• A known Robertsonian translocation.
• A known inversion that may affect chromosome balance in embryos.
• A history of recurrent pregnancy loss or previous pregnancies with chromosome abnormalities, where a rearrangement has been found.

This is not a complete list, and it is not a set of criteria for eligibility. Whether PGT-SR is technically possible and clinically useful depends on the specific rearrangement, the chromosomes involved, and the laboratory’s ability to design a reliable test. A genetics professional or a clinic with relevant expertise should make that assessment.

The PGT-SR process in outline

The exact steps vary by clinic, but the general sequence is similar to other forms of PGT.

1. Genetic review and test design. The rearrangement is reviewed, and the laboratory confirms whether it can build a reliable test. This may involve additional blood samples from the couple or family members.
2. IVF cycle. Eggs are collected and fertilised in the laboratory to create embryos.
3. Embryo biopsy. A small number of cells are removed from each embryo, usually at the blastocyst stage.
4. Laboratory analysis. The biopsy samples are analysed for the structural rearrangement.
5. Results and transfer planning. The clinic discusses which embryos are suitable for transfer, based on the results and other factors.

Timelines depend on the clinic, the laboratory and the complexity of the test. Some tests require more preparation than others. It is reasonable to ask how long the whole process is expected to take in your case.

What results can and cannot show

PGT-SR results are usually reported in terms of whether an embryo is balanced, unbalanced, or whether the result is informative. However, the exact reporting language varies. Some results may be uncertain, and some embryos may not provide a conclusive answer.

It is important to understand that:

• PGT-SR cannot detect every genetic or chromosomal condition.
• A balanced result does not guarantee a healthy pregnancy or child.
• An unbalanced result does not necessarily mean an embryo could never lead to a pregnancy, but it may be associated with a higher chance of miscarriage or a chromosome condition.
• Mosaicism (where cells in an embryo differ) can complicate interpretation.

A genetics professional or a clinician with relevant expertise should explain what a specific result means for your situation.

Limitations and alternatives

PGT-SR is one option among several. Alternatives may include:

• IVF without PGT-SR, with or without other forms of testing.
• Using donor gametes, if that is acceptable and available.
• Diagnostic testing during pregnancy, such as chorionic villus sampling or amniocentesis, if a pregnancy occurs.
• Choosing not to pursue IVF or genetic testing at all.

Each option has its own trade-offs. PGT-SR requires an IVF cycle, which involves medications, monitoring and costs. It does not remove all uncertainty. Some people find that the information helps them make decisions; others may decide that the additional steps are not right for them.

Questions to ask a clinic in Thailand

If you are considering PGT-SR in Thailand, these questions can help you compare clinics and understand what is involved.

• Does the clinic have experience with my specific type of rearrangement?
• Which laboratory performs the PGT-SR analysis, and how is the test designed?
• What samples are needed from me or my partner, and when?
• How are results reported, and what does an inconclusive result mean?
• What are the estimated costs for the IVF cycle, the PGT-SR test, and any additional appointments?
• What is the expected timeline from consultation to embryo transfer?
• Who will explain the results to me, and is genetic counselling available?
• What are the alternatives if PGT-SR is not possible or not recommended?

It is also reasonable to ask for a written summary of the proposed plan and costs before you commit.

Practical next steps

• Gather your genetic test results and any relevant family history.
• Speak with a genetics professional, if you have not already, to understand your rearrangement and its implications.
• Contact clinics that offer PGT-SR and ask the questions above.
• Compare the information you receive, including costs, timelines and laboratory arrangements.
• Take time to consider whether PGT-SR fits your goals and circumstances.

You can also read more general information about PGT in Thailand and browse our guides for related topics. If you have further questions, our FAQ section may help.

Frequently asked questions

Is PGT-SR the same as PGT-A?

No. PGT-A looks at chromosome number, while PGT-SR looks at chromosome structure in people with a known rearrangement. They answer different questions and are used in different situations.

Can PGT-SR guarantee a healthy baby?

No. PGT-SR can provide information about chromosome structure in embryos, but it cannot detect every possible health issue, and it does not guarantee a pregnancy or a healthy child.

Do I need a genetics professional to have PGT-SR?

It is strongly recommended. A genetics professional can confirm the type of rearrangement, explain what PGT-SR can and cannot show, and help you understand your options.

Is PGT-SR available in Thailand?

Some clinics in Thailand may offer PGT-SR, but availability varies. You should ask each clinic directly about their experience with your specific rearrangement and the laboratory they use.

What if PGT-SR results are inconclusive?

Inconclusive results can happen. The clinic should explain what the result means for that embryo and discuss whether further testing or a different approach is possible.

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.