PGT (preimplantation genetic testing) is a laboratory step that can be added to an IVF cycle. After eggs are fertilised and embryos begin to develop, a small number of cells may be removed from each embryo and tested for specific chromosome or gene findings. In Thailand, as elsewhere, PGT is optional rather than automatic: it is a decision made with your treating clinician, based on your history, your reasons for testing and what the result could realistically change. PGT cannot guarantee a pregnancy, a live birth or a healthy child, and it is not necessary or suitable for everyone.
At a glance
- PGT-A looks at chromosome number (for example, extra or missing chromosomes).
- PGT-M looks for a known single-gene condition that runs in a family.
- PGT-SR relates to known structural chromosome rearrangements, such as a translocation.
- Testing happens in the laboratory after fertilisation, before any embryo transfer.
- Results are probabilities and risk information, not promises.
- Availability, eligibility, cost and timelines vary by clinic and must be confirmed directly.
What PGT is, and what it is not
PGT is a screening or diagnostic laboratory technique performed on embryos created through IVF. It is not a treatment for infertility, and it does not improve the quality of an embryo. Instead, it provides additional information that you and your clinician may use when deciding which embryo(s) to consider transferring, or whether to consider other options.
It is important to separate three ideas that are sometimes blurred together:
- What the test looks at: chromosome number, a specific gene change, or a structural chromosome arrangement.
- What the result means: a laboratory finding that carries a certain level of uncertainty.
- What happens next: a clinical decision that depends on your full situation, not on the test result alone.
PGT is not a guarantee of success, and it does not replace other forms of prenatal testing or genetic counselling. Some patients choose IVF without PGT; others choose PGT for specific reasons. Both paths can be reasonable.
The three main types of PGT
The umbrella term “PGT” covers different tests with different purposes. The table below summarises the broad differences. Your clinic will explain which, if any, applies to you.
| Type | What it looks at | Typical reason it is discussed | Key limitation |
|---|---|---|---|
| PGT-A | Chromosome number (aneuploidy screening) | Age-related risk, recurrent implantation failure or recurrent pregnancy loss, or when a clinic offers it as an option | It does not read the whole genetic code, and it cannot guarantee a healthy pregnancy |
| PGT-M | A known single-gene condition in the family | When a specific inherited condition is known and a lab can build a test for it | Requires prior genetic information and lab setup; not all conditions are equally straightforward |
| PGT-SR | Structural chromosome rearrangements (for example, translocations) | When a parent carries a known structural rearrangement | Interpretation can be complex; results need specialist explanation |
Some clinics may also discuss other laboratory techniques, such as mitochondrial DNA testing or polygenic risk scoring. These are not the same as PGT-A, PGT-M or PGT-SR, and their clinical role is still debated. Ask your clinic to explain exactly what is being offered and what evidence supports it.
How PGT fits into an IVF cycle in Thailand
The exact sequence varies by clinic, but the general shape of a PGT cycle is similar in most settings. The steps below are a planning framework, not a protocol. Your clinic will give you its own instructions.
- Initial consultation and testing. You discuss your history, reasons for considering PGT, and whether it is appropriate. You may be asked to provide prior genetic test results or family information.
- Ovarian stimulation and monitoring. Medication is used to encourage multiple eggs to mature, with monitoring scans and blood tests. Your clinic decides the protocol.
- Egg retrieval and fertilisation. Eggs are collected and combined with sperm in the laboratory to create embryos.
- Embryo development. Embryos are observed for several days. Not all fertilised eggs develop into embryos suitable for testing or transfer.
- Biopsy. If PGT is planned, a few cells are removed from each embryo at a suitable stage. This is a laboratory procedure.
- Testing and reporting. The sampled cells are analysed. The time needed depends on the test and the laboratory.
- Results discussion. You and your clinician review the findings, including any uncertainty, and discuss options.
- Transfer or storage. Depending on results and your preferences, an embryo may be transferred, frozen for later, or not used. Some embryos may be reported as “no result” or “inconclusive,” which requires a further conversation.
Because PGT adds laboratory steps, it can extend the overall timeline and add cost. The exact amounts and waiting times are clinic-specific and should be confirmed in writing before you commit.
Who might consider PGT — and who might not
PGT is a personal decision. There is no single rule that applies to everyone. The following categories are commonly discussed, but they are conversation starters, not eligibility criteria.
- Known inherited condition in the family: PGT-M may be discussed when a specific gene change is known.
- Known structural chromosome rearrangement: PGT-SR may be discussed when a parent carries a translocation or similar finding.
- History of recurrent pregnancy loss or repeated implantation failure: PGT-A may be offered as one option, though evidence and guidelines vary.
- Advanced maternal age: Some clinics discuss PGT-A because chromosome number errors become more common with age, but it is not a guarantee of a better outcome.
- Previous pregnancy or child with a chromosome condition: A clinician may discuss PGT-A or other testing.
- No specific risk factors: Some patients choose PGT for personal reasons; others choose not to. Both choices can be valid.
PGT is generally not a first-line recommendation for every IVF patient. It may be less useful, or not useful, when there is no clear question the test can answer. A genetic counsellor or your treating clinician can help you weigh the potential benefits and limitations.
Understanding PGT results and their limits
PGT results are laboratory findings, not diagnoses of a future child. They can be reported in different ways, and the meaning depends on the test and the laboratory.
- “Normal” or “euploid” (PGT-A): The tested cells showed the expected number of chromosomes. This reduces, but does not eliminate, the chance of a chromosome condition. It cannot rule out all genetic conditions, and it does not guarantee a pregnancy.
- “Abnormal” or “aneuploid” (PGT-A): The tested cells showed an extra or missing chromosome. This information may influence which embryo is considered for transfer, but it is not a prediction of a child’s health or abilities.
- “Mosaic”: The tested cells showed a mix of normal and abnormal findings. Mosaic results are complex, and their interpretation is an active area of discussion. Ask your clinic what a mosaic result would mean in your case.
- “No result” or “inconclusive”: The test did not produce a clear answer. This can happen for technical reasons. Your clinic will explain the options, which may include re-testing, transferring without a result, or not using the embryo.
- PGT-M and PGT-SR results: These are usually reported in relation to the specific condition or rearrangement being tested. They require careful explanation by a specialist.
No test is perfect. PGT can produce false results in rare cases, and it cannot detect every possible genetic or health issue. For this reason, many clinics still recommend standard prenatal screening or diagnostic testing during pregnancy, such as ultrasound, blood tests, or chorionic villus sampling/amniocentesis, depending on your situation.
Alternatives and complementary options
PGT is one option among several. Depending on your situation, you might also discuss:
- IVF without PGT: Transferring embryos based on standard laboratory assessment.
- Donor eggs or donor sperm: Which may change the genetic questions being considered.
- Prenatal screening and diagnosis: Tests during pregnancy that can provide information about the fetus.
- Genetic counselling: A conversation with a specialist to understand risks, inheritance patterns and testing options.
- Preimplantation genetic testing for a specific condition (PGT-M) using a previously established lab protocol: Sometimes a lab needs time to prepare a custom test.
These options are not mutually exclusive. Your clinician can help you understand how they might fit together.
Practical questions to ask a clinic in Thailand
Because PGT services, laboratory arrangements and pricing vary, it helps to ask direct questions. You can use the list below as a starting point.
- Which type of PGT are you recommending for my situation, and why?
- What is the evidence that this test will change my care or outcome?
- Who performs the biopsy and the laboratory analysis? Is any part sent to another laboratory?
- What are the possible results, including “no result” or “mosaic,” and what would each mean for my options?
- What are the total costs, including consultation, medication, laboratory, biopsy, testing, storage and transfer? Are there separate fees for genetic counselling?
- How long does testing take, and how does it affect the overall timeline?
- What happens to embryos that are not transferred or not used?
- What are the legal and regulatory requirements in Thailand for my situation, and what documents should I prepare?
- Do you recommend prenatal testing during pregnancy even after PGT?
- Can I speak with a genetic counsellor before deciding?
Ask for written information where possible, and take time to consider your options. It is reasonable to seek a second opinion.
Next-step checklist
- Clarify your personal reasons for considering PGT.
- Gather any prior genetic test results or family history information.
- Ask your clinic which PGT type, if any, is relevant to you.
- Request a clear cost breakdown and timeline in writing.
- Ask about the laboratory’s experience and quality processes.
- Discuss the limits of testing and what a result can and cannot tell you.
- Consider genetic counselling before making a decision.
- Confirm legal, travel and documentation requirements with the clinic and relevant authorities.
PGT can be a useful tool in some situations, but it is not a guarantee and not a universal requirement. The most important step is an honest conversation with a qualified clinician who knows your history and can explain what testing might realistically offer you.
Frequently asked questions
Is PGT the same as IVF?
No. IVF is the process of creating embryos outside the body. PGT is an optional laboratory test that can be performed on those embryos before transfer. You can have IVF without PGT.
Does PGT guarantee a healthy baby?
No. PGT can provide information about specific chromosome or gene findings, but it cannot guarantee a pregnancy, a live birth or a child without any health condition. It does not replace prenatal testing, and no test is perfect.
Who is PGT suitable for?
PGT may be discussed for several reasons, such as a known inherited condition in the family, a known structural chromosome rearrangement, a history of recurrent pregnancy loss, or advanced maternal age. It is not automatically recommended for everyone, and suitability is a clinical decision made with your treating clinician.
What does a “mosaic” PGT result mean?
A mosaic result means the tested cells showed a mix of normal and abnormal findings. The interpretation is complex and depends on the specific situation. Your clinic or a genetic counsellor should explain what it could mean for your options.
Can I have PGT in Thailand if I am an international patient?
Many international patients travel to Thailand for IVF, and some clinics offer PGT. Availability, eligibility, legal requirements, documentation and costs vary by clinic and by your individual situation. You should confirm these details directly with the clinic and, where relevant, with the appropriate authorities before making travel plans.
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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.