Questions to Ask a Genetic Counsellor About Combining PGT-M and PGT-A

PGT-M and PGT-A are not two versions of the same test. PGT-M looks for a known single-gene condition that runs in a family; PGT-A looks at chromosome number in the embryo. When a clinic plans both, the laboratory is being asked to answer two separate questions from cells taken in a single biopsy. That is why the counselling conversation matters: it is where test design, limitations and reporting responsibilities get pinned down before any cycle begins.

You do not need to arrive with technical knowledge. You do need to arrive with the right questions and the right records. Below is a way to organise both.

Start with what each test is actually asking

It helps to separate the two layers before discussing how they combine. PGT-M concerns a known monogenic condition, while PGT-SR concerns chromosomal structural rearrangements — a different question again. PGT-A assesses chromosome number in cells sampled from an embryo. Each test addresses a distinct question, and a treating team and genetic counsellor should discuss the relevant family history, test design and suitability for your situation.

If you are still sorting out which test is which, a plain-language comparison of PGT-A, PGT-M and PGT-SR is a reasonable place to start before the appointment. The goal of the counselling session is not to re-learn definitions but to apply them to your family.

Test design: the questions that shape the whole cycle

Test design is where most of the practical uncertainty sits when two tests are combined. Ask these directly, and ask for the answers in writing if the appointment is remote.

• Same sample or separate biopsies? Can the laboratory perform both the PGT-M and PGT-A analysis on the same trophectoderm sample, or would a second biopsy be needed? A second biopsy is not a neutral detail — embryo biopsy can cause damage and prevent further development, so the number of sampling events is worth clarifying.
• How is the PGT-M assay built for our family? PGT-M testing is customised to a specific known condition and family variant. Ask how the assay is designed, what validation steps precede clinical use, and how long that preparation takes relative to your intended cycle dates.
• Are linked markers needed, and what if we are uninformative? Some PGT-M designs rely on informative genetic markers flanking the variant. Ask whether your family’s results provide enough information, and what the laboratory does if they do not — for example, whether additional family samples would be requested.
• How does whole-genome amplification interact with the two readouts? Both analyses typically begin from amplified DNA from the same few cells. Ask how the laboratory handles the possibility that amplification or the PGT-M assay itself affects the quality of the chromosome-number readout, and whether one test is prioritised if sample quality is limited.
• What happens to embryos that are unaffected by the PGT-M result but abnormal on PGT-A? The two results can point in different directions. Ask in advance how such embryos would be classified and discussed.

Limitations: what neither test can promise

This is the part patients most often wish they had asked about earlier. A combined report can look authoritative while still carrying real uncertainty at both layers.

PGT-A has recognised limitations and can produce incorrect findings. A mosaic PGT-A result is inferred from intermediate chromosome copy-number findings in a biopsy sample; technical factors can contribute to such findings, and a sampled result does not establish the cell composition of the whole embryo. In other words, the report describes the sample, not a confirmed diagnosis of the embryo.

PGT-M carries its own boundaries. It addresses the specific variant the assay was designed for; it is not a general screen for other genetic conditions. Either layer can return a no-result or an inconclusive call, and the laboratory may or may not be able to re-test.

Ask your counsellor to state plainly that neither test guarantees implantation, a successful pregnancy or a healthy child, and to explain what a no-result would mean for your decision-making before you are in the position of receiving one. If you want to prepare for that scenario specifically, the questions in the guide to no-result PGT reports pair well with this conversation.

Reporting: who explains which part, and how

A combined report has more than one section, and it is reasonable to ask who owns each one.

• Which clinician or counsellor explains the PGT-M interpretation, and who explains the PGT-A interpretation?
• If the two results are discordant or one is uninformative, who coordinates the discussion and in what timeframe?
• What confirmatory testing during a later pregnancy might be discussed, and who would arrange it?
• Which results will be released to you directly, and in what format?

These are not bureaucratic questions. They determine whether you receive one coherent explanation or two partial ones. A useful companion read is the discussion of who should explain PGT findings and treatment options.

Records to gather before the appointment

Counselling about a combined test is only as specific as the information the counsellor has. Before a remote or in-person appointment, collect:

• The genetic test report confirming the family variant, including the gene, the specific change and the laboratory that reported it.
• Relevant family history, including which relatives are affected and how they are related to you.
• Reports from any previous IVF or PGT cycles, including biopsy, amplification or no-result information.
• Names and contact details of the clinicians who ordered the original genetic testing, in case the laboratory needs to follow up.

If you are consulting a clinic in Thailand from abroad, it also helps to confirm the appointment format, the language of the consultation, whether an interpreter is needed, and how documents should be sent. A terminology worksheet prepared for a remote consultation can reduce misunderstandings about terms such as informative, no-result and mosaic.

A worked planning example

Suppose a couple knows the family variant and has an appointment with a counsellor six weeks before a planned cycle. A practical preparation sequence might look like this:

1. Send the original genetic report and family history ahead of the appointment, and ask whether any relative’s sample would be needed for marker work.
2. Ask in writing whether both tests can run on one biopsy sample, and what the laboratory’s fallback is if sample quality is limited.
3. Ask for a short written summary of what a no-result, an inconclusive PGT-M call or a mosaic PGT-A result would each mean for next steps.
4. Confirm which named clinician will explain each part of the report and how results reach you.
5. Ask what the timeline for assay preparation means for your intended dates, and keep that answer with your cycle planning notes.

None of these steps requires you to interpret a result yourself. They simply make sure the clinical team has what it needs and that you know where each answer will come from.

Where coordination ends and clinical advice begins

Patients can and should ask licensed clinicians about diagnosis, options, risks, reports and their individual chances — that is exactly what the counselling appointment is for. A patient coordination service works on a different layer: organising records, requesting appointments and remote consultation formats, clarifying language needs, and helping with follow-up communication after you return home. It does not interpret genetic results, advise on test choice or predict outcomes. If you would like help assembling records and questions before approaching a clinic, you can request a case review and the scope will be confirmed with you individually.

Frequently asked questions

Can PGT-M and PGT-A be done on the same embryo biopsy?

That is a laboratory design question, and the answer depends on the clinic and the assay. Ask your counsellor or treating team directly whether both analyses can run on the same trophectoderm sample, and what the plan is if sample quality is limited. A second biopsy is not a trivial step, since embryo biopsy can cause damage and prevent further development.

If PGT-M says an embryo is unaffected, does a PGT-A result still matter?

They answer different questions. PGT-M addresses the specific family variant, while PGT-A looks at chromosome number in the sampled cells. A combined report can therefore contain two results that point in different directions. Ask in advance how such embryos would be classified and discussed, rather than deciding in the moment.