At a glance
A plain-language guide to reading your PGT-A report from a Thai lab, understanding common result categories, and preparing questions for your care team.
If you have just received a PGT-A report from a laboratory in Thailand, the first thing to know is that the report is a technical document, not a verdict. It describes what the laboratory observed in the small number of cells it sampled from each embryo. Turning those observations into a decision for your treatment requires your fertility doctor, and often a genetic counsellor, to place the result alongside your age, your history, the number of embryos available and your own priorities. This guide explains the common result categories in plain language and suggests questions you can bring to your care team. It is general education, not medical advice, and it cannot tell you what any specific result means for you.
At a glance
- PGT-A looks at chromosome number, not at specific gene mutations.
- Reports usually sort embryos into categories such as euploid, aneuploid, mosaic or inconclusive.
- “Euploid” is not a guarantee of pregnancy or a healthy child, and “aneuploid” is not always a simple yes-or-no answer.
- Mosaic results sit in a grey zone and are often the hardest to interpret.
- Your clinic’s own policies, your history and your preferences all shape what happens next.
What PGT-A actually tests
Preimplantation genetic testing for aneuploidy (PGT-A) is a laboratory test performed on a few cells taken from an embryo, usually at the blastocyst stage. The test estimates whether the embryo has the expected number of chromosomes, or whether there appear to be extra or missing chromosomes. A typical human embryo has 46 chromosomes arranged in 23 pairs. When the number is different, the condition is called aneuploidy.
PGT-A is different from PGT-M, which looks for a specific inherited condition that runs in a family, and from PGT-SR, which looks at chromosome rearrangements such as translocations. If your report mentions PGT-A, it is focused on chromosome number rather than a named gene. Some clinics combine tests, so it is worth checking which test or tests were actually run on your embryos.
It also helps to remember what PGT-A is not. It is not a full genome screen, it does not predict intelligence, appearance or most adult-onset conditions, and it cannot confirm that an embryo will implant, grow normally or result in a healthy baby. It is one piece of information among many.
Why results can be difficult to read
Embryos are not uniform, and the cells sampled for testing are a tiny fraction of the whole embryo. A few practical points explain much of the confusion patients feel when they open a report:
- Sampling is limited. The lab works with a small number of cells, so the result is an estimate rather than a complete picture of every cell in the embryo.
- Some embryos are mosaic. That means the sampled cells are not all the same, with some appearing to have the expected chromosome number and others not.
- Technical factors matter. Sample quality, the laboratory’s platform and its thresholds for calling a result can all influence how a finding is reported.
- Reports use different wording. Two laboratories may describe similar findings with different labels or thresholds, which is one reason comparing reports from different clinics can be misleading.
Because of these factors, a result that looks alarming on paper may be discussed quite differently in a consultation, and a result that looks reassuring still carries uncertainty.
Common PGT-A result categories
The exact wording varies by laboratory, but most reports use a small set of categories. The table below summarises the general meaning of each. It is a starting point for your conversation with your care team, not a substitute for it.
| Category | What it generally means | Why it needs clinical context |
|---|---|---|
| Euploid | The sampled cells showed the expected number of chromosomes. | Reduces but does not eliminate the chance of aneuploidy in the rest of the embryo, and does not guarantee implantation or a healthy pregnancy. |
| Aneuploid | The sampled cells showed an extra or missing chromosome. | Some aneuploidies are more serious than others, and the clinical significance depends on which chromosome is involved. |
| Mosaic | The sampled cells were a mix of euploid and aneuploid patterns. | The proportion and type of mosaic cells, and the laboratory’s thresholds, affect how the result is interpreted. |
| Inconclusive or no result | The laboratory could not produce a reliable reading. | This is a technical outcome, not a finding about the embryo itself, and options may include re-biopsy or proceeding without a result. |
| Complex or multiple abnormalities | More than one chromosome appears affected. | These results are usually discussed in detail with a genetic counsellor. |
Some reports also include a percentage or a confidence note. Ask your clinic to walk you through what those numbers mean in their laboratory’s system, because thresholds are not standardised across all labs.
Understanding mosaic embryo results
Mosaic results are often the most stressful part of a PGT-A report, partly because the word itself sounds definitive when it is not. In practice, mosaicism exists on a spectrum. A report may describe low-level or high-level mosaicism, or it may simply flag the embryo as mosaic without further detail.
Several factors shape how a mosaic result is handled:
- The proportion of cells that appear aneuploid in the sample.
- Which chromosome or chromosomes are involved.
- Whether the finding is a full chromosome issue or a smaller segment.
- The number of other embryos available and their results.
- Your clinic’s internal policy and the counselling it provides.
Some clinics may consider transferring certain mosaic embryos after detailed counselling, while others may not. There is no single international rule, and practices differ. If you receive a mosaic result, it is reasonable to ask for a dedicated counselling session rather than deciding in the moment.
What PGT-A can and cannot tell you
PGT-A can provide information that some patients and clinicians use when choosing which embryo to transfer first, particularly when several embryos are available. It may also help some patients avoid transferring an embryo with a chromosome pattern that is unlikely to develop.
What it cannot do is guarantee a live birth, rule out all genetic conditions, predict how a child will develop, or replace prenatal testing later in pregnancy. It also does not improve the quality of any individual embryo; it only provides information about the embryos you already have. For some patients, the information changes decisions. For others, it adds cost and complexity without changing the plan. Whether to use PGT-A at all is a personal decision that depends on your circumstances and should be discussed with your doctor.
Questions to ask your care team
Bring your report to your next appointment and consider asking:
- Which specific test was run on my embryos, and what does the report’s wording mean in your laboratory?
- How many embryos were tested, and what was the result for each one?
- For any mosaic result, what proportion of cells was affected, and which chromosome was involved?
- What are the clinic’s general practices for transferring embryos with this type of result?
- What would happen if we transferred this embryo, and what would happen if we did not?
- Are there alternative options, such as further testing, a different embryo, or proceeding without PGT-A for future cycles?
- Would a referral to a genetic counsellor be helpful in my case?
- What costs are associated with any additional testing or counselling?
It is also reasonable to ask for the report in writing, in a language you read comfortably, and to request a follow-up conversation if the first explanation was not clear.
Next steps after receiving your report
- Save a copy of the full report, including any technical appendix.
- Write down your questions before the appointment so you do not lose them in the moment.
- Ask for the result to be explained in the context of your age, history and the number of embryos available.
- Take notes, or ask whether you may record the consultation.
- If a mosaic or complex result is involved, ask specifically about counselling.
- Give yourself time. A PGT-A report rarely requires an immediate decision on the same day.
You can also review our PGT in Thailand overview, browse the patient guides, or check the frequently asked questions for more background before your appointment.
Frequently asked questions
Does a euploid PGT-A result mean the embryo is perfect?
No. A euploid result means the sampled cells showed the expected number of chromosomes, which is generally reassuring. It does not guarantee implantation, a continuing pregnancy or a healthy child, because the test samples only a few cells and cannot assess every aspect of embryo health.
What does a mosaic embryo result mean for transfer?
Mosaic means the sampled cells were a mix of euploid and aneuploid patterns. How a mosaic embryo is handled varies between clinics and depends on factors such as the proportion of affected cells and which chromosome is involved. This is usually discussed in a dedicated counselling session rather than decided quickly.
Can I get a second opinion on my PGT-A report from a Thai lab?
Many patients ask their treating clinic to review the report again or seek a second clinical opinion. Whether a laboratory will re-analyse a sample depends on its own policies and on whether any sample material remains. Ask your clinic what is possible in your case.
Is PGT-A required before an IVF transfer in Thailand?
PGT-A is not universally required, and practices differ between clinics and between patients. Whether it is offered or recommended depends on your medical history, your age, the number of embryos available and your own preferences. Discuss the benefits and limitations with your treating doctor.
What should I do if my report says inconclusive or no result?
An inconclusive result is a technical outcome, not a finding about the embryo. Options may include re-biopsy if the embryo is still suitable, transferring without a result, or prioritising other embryos. Ask your clinic which options apply to your situation.
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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.
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