PGT for Balanced Translocation Carriers in Thailand: A Carrier-Specific Guide

If you carry a balanced translocation, your chromosomes are rearranged but no genetic material is missing or extra. Many carriers are healthy and only discover the rearrangement after recurrent miscarriage, failed implantation or a child diagnosed with an unbalanced chromosome pattern. PGT-SR (preimplantation genetic testing for structural rearrangements) is a laboratory test performed on embryos created through IVF. It aims to identify embryos with an unbalanced chromosome pattern so that those embryos are not prioritised for transfer. It cannot guarantee a pregnancy, a live birth or a healthy child, and it is not the right path for every carrier. In Thailand, availability, laboratory methods, costs and legal requirements vary by clinic and should be confirmed directly.

At a glance

• PGT-SR is designed for people with a known structural chromosome rearrangement, such as a reciprocal or Robertsonian translocation.
• It tests embryos, not the carrier, and it does not change the translocation you carry.
• Results are probabilistic: a “normal/balanced” result reduces but does not eliminate the chance of an affected pregnancy.
• PGT-A and PGT-M answer different questions and may or may not be combined with PGT-SR.
• Counselling before and after testing is a core part of the pathway, not an optional extra.

What a balanced translocation means for reproduction

A translocation happens when pieces of two or more chromosomes break and rejoin in a different arrangement. In a reciprocal translocation, segments are exchanged between two chromosomes. In a Robertsonian translocation, two acrocentric chromosomes fuse near their centromeres, and the carrier typically has 45 chromosomes instead of 46.

Because the carrier’s own genetic material is complete, a balanced translocation usually causes no health problems for the carrier. The difficulty arises during egg or sperm formation. When chromosomes pair and separate, the resulting embryo may receive a balanced arrangement like the parent’s, a completely typical arrangement, or an unbalanced arrangement with missing or extra chromosome material. Unbalanced embryos are associated with miscarriage, failed implantation and, in some cases, a child with developmental or health concerns.

The specific chromosomes involved, the exact breakpoints and the size of the rearranged segments all influence the possible outcomes. This is why a genetics professional reviews your karyotype and, where relevant, your partner’s karyotype before any IVF cycle is planned.

How PGT-SR fits into an IVF pathway

PGT-SR is not a standalone treatment. It sits inside an IVF cycle, and the sequence matters.

1. Genetic confirmation. A karyotype or equivalent test confirms the translocation and identifies the chromosomes involved.
2. Pre-test counselling. A genetics professional explains the possible embryo outcomes, the limits of testing and the alternatives.
3. IVF and embryo development. Eggs are collected and fertilised, and embryos are cultured to a stage suitable for biopsy.
4. Embryo biopsy. A small number of cells are removed from each embryo for laboratory analysis.
5. Laboratory analysis. The laboratory uses a validated method to assess the chromosomes relevant to the translocation.
6. Results and counselling. Results are reviewed with you, including any embryos that could not be classified.
7. Transfer decision. You and your clinician decide which embryo, if any, to transfer, taking into account the result, embryo quality and your preferences.

Some clinics may also offer PGT-A, which screens for extra or missing copies of chromosomes across the embryo, or PGT-M, which targets a specific single-gene condition. Whether either is appropriate alongside PGT-SR depends on your history and should be discussed case by case.

PGT-A, PGT-M and PGT-SR: what each test is for

Test	Main question it addresses	Typical situation
PGT-A	Does the embryo have an abnormal number of chromosomes overall?	Often discussed with advancing maternal age or recurrent implantation failure
PGT-M	Does the embryo carry a specific inherited single-gene condition?	When a known familial gene variant has been identified
PGT-SR	Does the embryo have an unbalanced form of a known structural rearrangement?	When one partner carries a balanced translocation

These tests are not interchangeable. A normal PGT-A result does not rule out an unbalanced translocation, and PGT-SR does not screen for unrelated single-gene conditions. If you are unsure which test applies to you, ask for a written explanation of the reasoning.

What PGT-SR results can and cannot tell you

Laboratory reports usually describe embryos in categories such as balanced/normal, unbalanced, or inconclusive. The exact wording and the proportion of inconclusive results depend on the laboratory method, the chromosomes involved and the quality of the biopsy sample.

• Can: identify many embryos with an unbalanced chromosome pattern related to the known translocation.
• Can: help you and your clinician prioritise which embryos to consider for transfer.
• Cannot: guarantee that a transferred embryo will implant, develop normally or result in a healthy child.
• Cannot: detect every possible chromosome problem, including some changes unrelated to the translocation.
• Cannot: replace prenatal testing or diagnostic testing during pregnancy if you choose to have it.

Mosaic results, where different cells in the biopsy show different patterns, can be particularly difficult to interpret. Ask how your clinic handles these results and whether re-analysis or additional counselling is offered.

Who may consider PGT-SR, and who may not

PGT-SR is generally discussed when a balanced translocation has been confirmed in one partner and there is a history of miscarriage, repeated implantation failure or a previous affected pregnancy. It may also be considered before a first pregnancy, depending on the specific rearrangement and personal circumstances.

It may be less relevant, or not relevant at all, when:

• No translocation has been confirmed by genetic testing.
• The rearrangement is known to carry a very low risk of unbalanced offspring.
• You would not pursue IVF for other reasons.
• You prefer to conceive naturally and use prenatal diagnosis instead.

These are general considerations, not eligibility rules. Only your treating clinician and a genetics professional can advise on your individual situation.

Alternatives and complementary options

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

• Natural conception with monitoring. Some carriers conceive without assistance and use prenatal testing to assess the pregnancy.
• IVF without PGT-SR. Embryos are transferred without chromosome analysis of the translocation.
• Donor gametes. Using eggs or sperm from a donor without the translocation.
• Prenatal diagnosis. Chorionic villus sampling or amniocentesis during pregnancy, if you conceive.
• Adoption or fostering. For some people, building a family through other routes is the preferred path.

Each option has different medical, emotional, ethical and financial implications. A genetics counsellor can help you compare them without steering you toward a particular choice.

Counselling: what to expect and what to ask

Translocation counselling should cover your specific karyotype, the possible embryo outcomes, the limits of PGT-SR, the chance of inconclusive results and the option of prenatal testing. It should also address the emotional weight of recurrent loss and the uncertainty that remains even after testing.

Questions worth asking a clinic in Thailand:

• Which laboratory method do you use for PGT-SR, and how do you validate it for my translocation?
• What proportion of embryos typically return an inconclusive result in cases like mine?
• Who provides genetic counselling, and is it included in the quoted price?
• How do you handle mosaic or ambiguous results?
• What are the costs of the IVF cycle, biopsy, testing, storage and transfer, and which are separate?
• What documents or legal steps should I prepare as an international patient?
• What happens if no balanced/normal embryo is available after testing?

Planning and next steps

1. Gather your genetic test reports, including the full karyotype and any prior pregnancy records.
2. Ask for a pre-test counselling appointment with a qualified genetics professional.
3. Request a written summary of the proposed pathway, including which tests are included and which are optional.
4. Confirm the total cost structure in writing, including items that may be charged separately.
5. Ask how results will be communicated and what follow-up counselling is available.
6. Consider how you would like to proceed if results are inconclusive or if no suitable embryo is available.

For broader context on testing in Thailand, see our PGT in Thailand overview and the related guides. If you have a specific question about your situation, the FAQ section may help you prepare for a clinic conversation.

Frequently asked questions

Can PGT-SR guarantee a healthy baby if I carry a balanced translocation?

No. PGT-SR can identify many embryos with an unbalanced chromosome pattern related to your translocation, but it cannot guarantee implantation, a live birth or a healthy child. Some chromosome changes are not detected by the test, and results can be inconclusive. Your clinician and a genetics professional can explain what the test can and cannot do in your specific case.

What is the difference between PGT-SR and PGT-A for translocation carriers?

PGT-A screens for extra or missing copies of chromosomes across the embryo, while PGT-SR is designed to assess the specific structural rearrangement you carry. A normal PGT-A result does not rule out an unbalanced translocation. Whether one or both tests are appropriate depends on your history and should be discussed with your clinician.

Do I need genetic counselling before PGT-SR in Thailand?

Pre-test counselling is strongly recommended because it explains the possible embryo outcomes, the limits of testing and the alternatives. Availability and format vary by clinic, so ask whether counselling is included and who provides it. Post-test counselling is also important, especially if results are inconclusive.

What happens if no balanced or normal embryos are found after PGT-SR?

This is a possible outcome, and it should be discussed before you start treatment. Your clinic may offer additional counselling, discuss another IVF cycle, or review alternatives such as donor gametes, natural conception with prenatal testing, or other family-building routes. There is no single correct next step; the decision depends on your circumstances and preferences.

Are there alternatives to PGT-SR for balanced translocation carriers?

Yes. Alternatives may include natural conception with prenatal diagnosis, IVF without PGT-SR, donor gametes, or adoption and fostering. Each option has different medical, emotional and financial implications. A genetics counsellor can help you compare them without recommending one path over another.

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.