PGT and IVF Success Rates in Thailand: What Testing Can and Cannot Change

PGT does not guarantee a live birth, and it does not improve the quality of any single embryo. What it can do is give you and your clinician more information about which embryos are most likely to be chromosomally normal, so that the embryo chosen for transfer is selected on evidence rather than appearance alone. Whether that changes your personal chance of a live birth depends on your age, your reason for testing, how many embryos you have, and how your clinic reports its results. This guide explains the moving parts so you can ask better questions in Thailand.

At a glance

• PGT-A screens embryos for extra or missing chromosomes; it does not repair them.
• PGT-M looks for a specific inherited condition known to run in a family.
• PGT-SR looks at chromosome rearrangements such as translocations.
• Testing may reduce the chance of transferring an embryo that is chromosomally abnormal, but it cannot promise pregnancy, live birth or a healthy child.
• Age remains one of the strongest influences on both embryo chromosome status and live birth odds.
• Success-rate figures are only comparable when the definitions behind them match.

What PGT actually does

Preimplantation genetic testing (PGT) is carried out on a small sample of cells taken from an embryo during IVF, usually at the blastocyst stage. The sample is analysed in a genetics laboratory, and the result is used to help decide which embryo(s) to consider for transfer.

There are three main categories:

• PGT-A (aneuploidy screening) — checks for an abnormal number of chromosomes. It is the type most often discussed in relation to IVF success rates.
• PGT-M (monogenic disease) — looks for a specific gene variant linked to a known inherited condition in the family.
• PGT-SR (structural rearrangement) — looks at chromosome rearrangements, such as a translocation, that may affect embryo viability.

Each type answers a different question. PGT-A is a screening test, not a diagnosis of the embryo’s future. PGT-M and PGT-SR are more targeted and are usually considered when there is a specific family or genetic history.

What PGT can and cannot change about live birth odds

It helps to separate two ideas that are often mixed together.

What PGT can change: the information available at the moment of transfer. If several embryos are available, testing may help identify those with a normal chromosome complement, so the transfer decision is based on more than embryo appearance or development speed.

What PGT cannot change: the underlying biology of your eggs, sperm or embryos. Testing does not make an abnormal embryo normal, does not increase the number of usable embryos, and does not remove the many other reasons why an embryo may not implant or a pregnancy may not continue. It also cannot guarantee that a transferred embryo will lead to a live birth.

This is why two patients with the same PGT result can have very different outcomes. The test is one input among many.

How age interacts with PGT outcomes

Age affects IVF in two connected ways. First, it influences how many eggs are available and how many become usable embryos. Second, it influences the proportion of those embryos that are chromosomally normal. Because PGT-A reports on chromosome status, its results tend to reflect these age-related patterns.

In practical terms, this means:

• Younger patients often have more embryos to test, which can make selection more meaningful.
• Older patients may have fewer embryos, so there may be less to choose between — and sometimes no embryo suitable for transfer after testing.
• A normal PGT-A result does not cancel out the effect of age on other factors, such as uterine environment or overall health.

PGT is therefore not a way to “reset” age-related odds. It is a way to gather information within the limits of the embryos you have.

How Thai clinics report success rates

Success-rate figures are only useful if you know what is being counted. When you see a number described as a “PGT success rate” or “live birth rate”, ask which of the following it refers to:

• The denominator — is it per cycle started, per egg retrieval, per embryo transfer, or per patient?
• The numerator — is it a positive pregnancy test, a clinical pregnancy, an ongoing pregnancy, or a live birth?
• The population — does it include all patients, or only a selected group such as younger patients or those with many embryos?
• The testing strategy — were all embryos tested, or only some? Was a fresh or frozen transfer used?
• The time period — rates can shift as laboratory methods and patient mix change.

Two clinics can quote very different numbers while both being accurate, simply because they are measuring different things. A high figure based on a narrow, favourable group is not directly comparable with a lower figure based on all comers.

Questions to ask a clinic in Thailand

These questions are designed to help you compare like with like, and to understand what a clinic’s numbers actually describe.

1. For patients similar to me — same age range, same reason for treatment — what outcomes do you typically see?
2. How do you define and calculate your live birth rate? Per transfer, per retrieval, or per patient?
3. Do your published or quoted figures include PGT and non-PGT cycles separately?
4. What proportion of your PGT cycles result in no embryo available for transfer?
5. Which PGT types do you offer, and who performs the genetic analysis?
6. What are the limitations of PGT in my situation, and what would you recommend if I chose not to test?
7. What are the costs of testing, and are they separate from the IVF cycle costs?
8. What is your policy on counselling before and after PGT?

Ask for the answers in writing where possible. A clinic that is comfortable explaining its definitions is usually easier to work with.

Alternatives and limitations to consider

PGT is one option, not the only one. Depending on your situation, you and your clinician may also discuss:

• Transfer without PGT — using embryo development and morphology to guide selection.
• Different transfer strategies — for example, fresh versus frozen embryo transfer.
• Further diagnostic testing — such as carrier screening for you or your partner, which may change which PGT type is relevant.
• Donor eggs or sperm — where these are legal and available, and where they fit your circumstances.

Limitations to keep in mind:

• PGT-A is a screening test and can occasionally give an unclear or inconclusive result.
• Mosaic results — where some cells are normal and others are not — require careful interpretation and specialist advice.
• Testing adds cost, time and laboratory steps to an IVF cycle.
• No test can guarantee a healthy child or a successful pregnancy.

Planning your next steps

If you are weighing PGT as part of IVF in Thailand, a practical sequence looks like this:

1. Clarify your reason for considering PGT — age, recurrent loss, family history, or something else.
2. Ask whether PGT-A, PGT-M or PGT-SR is relevant to that reason.
3. Request outcome data that matches your age range and situation, with clear definitions.
4. Ask what happens if no embryo is suitable for transfer after testing.
5. Confirm the full cost picture, including genetic counselling and any additional laboratory fees.
6. Check how results and counselling will be communicated to you, especially if you are travelling from abroad.
7. Take time to decide. PGT is a choice, not a requirement.

For more context, see our guides on IVF success rates in Thailand, PGT in Thailand, and our patient guides. If you have a specific question, our FAQ may help.

Frequently asked questions

Does PGT improve IVF success rates?

PGT can help select embryos with a normal chromosome complement for transfer, which may be useful in some situations. However, it does not guarantee pregnancy or a live birth, and it does not change the underlying quality of your embryos. Whether it improves your personal odds depends on your age, the number of embryos available, and your reason for testing. Discuss the expected benefit with your clinician.

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

PGT-A screens for abnormal chromosome number. PGT-M looks for a specific inherited condition known to run in a family. PGT-SR looks at structural chromosome rearrangements such as translocations. Each answers a different question, and the right one for you depends on your history and test results.

How should I interpret success rates quoted by clinics in Thailand?

Ask what the number measures: per cycle, per retrieval, per transfer, or per patient; whether it counts pregnancy or live birth; and which patients are included. Rates based on selected groups are not directly comparable with rates based on all patients. Request definitions in writing so you can compare fairly.

Can PGT tell me whether my embryo will lead to a healthy baby?

No. PGT provides information about chromosome number or a specific genetic variant, but it cannot predict all aspects of embryo development, pregnancy outcome or child health. It is one part of a broader clinical picture, and counselling can help you understand its limits.

What happens if no embryo is suitable for transfer after PGT?

This is a possible outcome, especially when few embryos are available. Ask your clinic in advance how they handle this situation, what alternatives exist, and what support or counselling is offered. Knowing the plan beforehand can help you prepare.

Continue your research

• How to interpret IVF success rates
• PGT in Thailand overview
• PGT and IVF guides

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.