PGT-A IVF in Thailand: A Guide to Chromosome Screening, Indications, and Embryo Transfer Decisions

PGT-A (preimplantation genetic testing for aneuploidy) is a laboratory test that checks embryos created through IVF for an abnormal number of chromosomes. It is not a treatment that improves embryo quality, and it does not guarantee a pregnancy. Instead, it provides information that you and your clinician can use when deciding which embryo(s) to transfer. In Thailand, PGT-A is offered at some fertility clinics, but availability, laboratory arrangements, and eligibility criteria vary. This guide explains the general process, common indications, and the questions worth asking before you commit.

At a glance

• What it is: A test on a few cells taken from an embryo, usually at the blastocyst stage.
• What it looks for: Extra or missing whole chromosomes (aneuploidy).
• What it does not do: It does not fix embryo chromosomes, guarantee implantation, or rule out all genetic conditions.
• Who may be offered it: Often discussed for older patients, recurrent miscarriage, repeated implantation failure, or after severe male factor infertility — but indications are individual.
• Key decision point: Whether the information would change which embryo is transferred or whether you would consider transferring an embryo with a detected abnormality.

What PGT-A actually tests

Human embryos often have the wrong number of chromosomes. This is called aneuploidy. Most aneuploid embryos do not implant, or they may lead to miscarriage. A small number can result in a live birth with a chromosome condition such as Down syndrome, but many others stop developing before birth.

PGT-A counts chromosomes. It does not read individual genes, so it cannot detect single-gene disorders like cystic fibrosis or Huntington’s disease. It also does not detect structural chromosome rearrangements such as translocations. Those require different tests: PGT-M for monogenic (single-gene) conditions and PGT-SR for structural rearrangements. If you have a known genetic condition in the family, your clinic may recommend PGT-M instead of, or in addition to, PGT-A.

Common indications for PGT-A

PGT-A is not routinely recommended for every IVF patient. Guidelines from professional bodies generally suggest it may be considered in specific situations, and the decision should be made with a qualified clinician who knows your history. Commonly discussed indications include:

• Advanced maternal age: The chance of aneuploidy increases with age, so some clinics discuss PGT-A more often with older patients.
• Recurrent pregnancy loss: If you have had multiple miscarriages, PGT-A may be one option to explore, though it does not explain all causes.
• Repeated implantation failure: When several good-quality embryos have not led to pregnancy, some clinicians consider PGT-A.
• Severe male factor infertility: Some evidence suggests a higher risk of chromosome abnormalities in embryos in these cases.
• Previous pregnancy or child with a chromosome condition: PGT-A may be discussed, though the specific condition matters.
• Patient preference after counselling: Some patients want as much information as possible before transfer, even without a specific indication.

In Thailand, as elsewhere, not every clinic offers PGT-A, and some may have their own criteria. It is reasonable to ask why PGT-A is being recommended in your case and what the alternatives are.

The PGT-A process in Thailand: step by step

The exact sequence can vary by clinic, but the general pathway looks like this:

1. IVF stimulation and egg retrieval: You undergo standard IVF, including medication to stimulate the ovaries and a procedure to collect eggs.
2. Fertilisation and embryo culture: Eggs are fertilised in the laboratory and grown for several days, usually until the blastocyst stage (day 5 or 6).
3. Embryo biopsy: A few cells are removed from the outer layer of the blastocyst (the trophectoderm), which will become the placenta. This is done by an embryologist. The embryo itself is not usually harmed, though biopsy carries a small risk and not all embryos survive the process.
4. Sample preparation and testing: The biopsied cells are prepared and analysed, either at the clinic’s laboratory or at a partner genetics laboratory. The method may be next-generation sequencing (NGS) or another technique.
5. Embryo freezing: In most cases, embryos are frozen after biopsy while waiting for results. This allows time for the test and for your uterus to be ready for transfer in a later cycle.
6. Results and counselling: A genetic counsellor or your doctor explains the results. Embryos are usually classified as euploid (normal chromosome number), aneuploid (abnormal), or sometimes mosaic (a mix of normal and abnormal cells).
7. Embryo transfer decision: If you have euploid embryos, one may be selected for transfer. If all embryos are aneuploid, transfer may not be recommended, and you may need to consider another cycle or other options.

Timelines vary. Some clinics can return results within a few days; others may take longer depending on laboratory logistics. Ask your clinic for a realistic estimate.

How results guide embryo transfer decisions

The main purpose of PGT-A is to help choose which embryo to transfer. If you have several embryos, PGT-A may identify those with a normal chromosome number, which could improve the chance of a successful pregnancy per transfer. However, it does not guarantee success, and some euploid embryos still do not implant.

If results show only aneuploid embryos, your clinician may advise against transferring them, as they are unlikely to lead to a healthy birth. Some clinics may discuss transferring mosaic embryos, but this is a complex area with ongoing debate. Mosaic results mean the biopsy found a mixture of normal and abnormal cells; the embryo may still be able to develop normally, but the evidence is not clear-cut. Your clinic should explain the uncertainties and help you weigh the options.

It is also possible that PGT-A leaves you with no embryos to transfer. This is an important risk to consider before starting, both emotionally and financially.

Limitations and alternatives

PGT-A is a screening test, not a diagnostic one. It can produce false results, and it does not detect all genetic problems. It also does not improve the quality of your embryos; it only provides information. Some studies suggest PGT-A may not improve live birth rates for all patients, and it may reduce the number of embryos available for transfer.

Alternatives include:

• Transferring embryos without PGT-A: Many healthy babies are born from untested embryos.
• Ultrasound and maternal blood screening during pregnancy: These can check for some chromosome conditions after pregnancy is established.
• Diagnostic tests during pregnancy: Such as chorionic villus sampling or amniocentesis, which are more invasive but can confirm a diagnosis.
• PGT-M or PGT-SR: If you have a known single-gene disorder or structural rearrangement, these may be more appropriate.

Discuss the pros and cons with a genetic counsellor or your fertility doctor. They can help you understand how PGT-A might apply to your specific situation.

Questions to ask a clinic in Thailand

Before choosing a clinic for PGT-A, consider asking:

• Is PGT-A offered at this clinic, and which laboratory performs the testing?
• What are the clinic’s criteria for recommending PGT-A? Do I meet them?
• What is the biopsy timing and technique? Who performs it?
• How are results reported, and what support is available to interpret them?
• What happens if all embryos are aneuploid or mosaic?
• What are the additional costs for biopsy, testing, and freezing?
• How long does it take to get results?
• What are the clinic’s success rates for PGT-A cycles, and how do they compare with untested cycles?

Be cautious of any clinic that guarantees a baby or quotes success rates without context. No treatment can promise a live birth.

Next steps

If you are considering PGT-A in Thailand, start by gathering information and asking direct questions. You may wish to:

• Review your medical history with a fertility specialist to see if PGT-A is relevant for you.
• Ask for a written summary of the process, costs, and possible outcomes.
• Consider speaking with a genetic counsellor, either at the clinic or independently.
• Explore our PGT in Thailand page for more context, browse our guides, and check the FAQ for common questions.

PGT-A is a personal decision. Take your time, ask for evidence, and choose a clinic that respects your questions and your autonomy.

Frequently asked questions

Is PGT-A required for IVF in Thailand?

No. PGT-A is an optional test, not a required part of IVF. Whether it is offered or recommended depends on your medical history and the clinic's practice. Some patients choose IVF without PGT-A.

Does PGT-A improve the chance of having a baby?

PGT-A can help select embryos with a normal chromosome number for transfer, which may improve the chance per transfer in some situations. However, it does not guarantee a pregnancy or a healthy baby, and it may not improve live birth rates for all patients. Discuss the evidence with your clinician.

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

PGT-A screens for extra or missing whole chromosomes (aneuploidy). PGT-M tests for a specific single-gene disorder, such as cystic fibrosis. PGT-SR tests for structural chromosome rearrangements, such as translocations. Your clinic can advise which, if any, is appropriate for you.

What happens if PGT-A shows all embryos are abnormal?

If all embryos are aneuploid, transfer is usually not recommended because they are unlikely to lead to a healthy birth. Your clinician will discuss options, which may include another IVF cycle, using donor eggs or sperm, or choosing not to pursue further treatment. This is a difficult situation, and counselling support is important.

Can PGT-A detect all genetic problems?

No. PGT-A only looks at chromosome number. It does not detect single-gene disorders, structural rearrangements, or many other genetic conditions. It also cannot predict all aspects of a child's health.

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.