If a single-gene disorder runs in your family, IVF with preimplantation genetic testing for monogenic disorders (PGT-M) may be one way to reduce the chance of passing it on. In Thailand, PGT-M is carried out as part of an IVF cycle: embryos are created in the laboratory, a small number of cells are tested, and embryos without the specific genetic change are usually prioritised for transfer. PGT-M is not a guarantee, not suitable for everyone, and not a substitute for genetic counselling. This guide explains the process, the questions to ask, and the limits to keep in mind.
At a glance
- What it is: PGT-M looks for a known single-gene change (mutation) in embryos created through IVF.
- Who it may suit: People with a known inherited condition, or carriers of a condition, confirmed by prior genetic testing.
- What it cannot do: It cannot guarantee a healthy child, detect every possible condition, or replace prenatal testing.
- Key first step: Genetic counselling and a laboratory feasibility check before treatment planning.
- Practical points to confirm: Cost components, timelines, legal and documentation requirements, and what happens to untested or affected embryos.
What PGT-M is and how it differs from other PGT types
Preimplantation genetic testing (PGT) is an umbrella term for tests done on embryos before transfer. The three main types answer different questions:
- PGT-A (aneuploidy): Checks for an abnormal number of chromosomes. It is not designed to find a specific inherited disease.
- PGT-M (monogenic): Looks for a specific single-gene change that is already known in the family. This is the type most relevant to inherited conditions such as cystic fibrosis, thalassaemia, spinal muscular atrophy, or Huntington’s disease.
- PGT-SR (structural rearrangements): Used when a parent has a known chromosome rearrangement, such as a translocation.
PGT-M is targeted. It only looks for the genetic change it was designed to detect. It does not screen for unrelated conditions, and it does not improve embryo quality or guarantee implantation.
Who might consider PGT-M
PGT-M is usually discussed when there is a known genetic risk. Common situations include:
- A parent has been found to carry a mutation linked to a specific disorder.
- Both parents are carriers of the same recessive condition.
- A previous child or pregnancy was affected by a single-gene disorder.
- A family history suggests a dominantly inherited condition.
Whether PGT-M is appropriate depends on the specific gene, the mutation, the inheritance pattern, and laboratory feasibility. A genetic counsellor or clinical geneticist can help you understand your options, including whether prenatal diagnosis or other approaches might be more suitable.
The PGT-M process step by step
- Genetic counselling and confirmation. A clinical genetics team reviews your family history and confirms the exact mutation, usually with a blood or saliva sample.
- Laboratory feasibility check. The genetics laboratory assesses whether a reliable test can be built for your specific mutation. Not every mutation is straightforward to test.
- IVF cycle. Ovarian stimulation, egg retrieval, and fertilisation are carried out as in standard IVF.
- Embryo biopsy. A few cells are removed from each embryo, usually at the blastocyst stage.
- Genetic analysis. The biopsy samples are tested for the specific mutation. Results are typically available within a few days to a couple of weeks, depending on the laboratory.
- Embryo transfer. Embryos without the mutation are usually prioritised. Some embryos may be affected or inconclusive.
- Follow-up. Your clinic will discuss remaining embryos, storage, and whether confirmatory prenatal testing is recommended.
Timelines vary. Some laboratories need weeks or months to design and validate a PGT-M test before your IVF cycle can begin.
Understanding PGT-M results
PGT-M results are not always a simple yes or no. Possible outcomes include:
- Unaffected: The specific mutation was not detected.
- Affected: The mutation was detected.
- Carrier: For recessive conditions, an embryo may carry one copy of the mutation without being affected.
- Inconclusive or no result: The test did not give a clear answer, which can happen for technical reasons.
Even a clear result does not guarantee a healthy child. PGT-M cannot rule out all genetic conditions, and some disorders can arise from new mutations not present in the parents. Many clinics recommend confirmatory testing during pregnancy, such as chorionic villus sampling or amniocentesis, to check the result.
Limits, uncertainties, and alternatives
PGT-M reduces the chance of transferring an embryo with a specific mutation, but it has limits:
- It cannot detect every genetic or chromosomal condition.
- It does not guarantee pregnancy, live birth, or a child without health issues.
- Some embryos may be unsuitable for testing or transfer.
- Mosaic results (where cells differ) can complicate interpretation.
- Costs and access vary, and not all laboratories offer every test.
Alternatives to discuss with your clinical team include:
- IVF without PGT-M, with prenatal diagnosis during pregnancy.
- Using donor eggs or sperm.
- Preimplantation genetic testing for other purposes, if relevant.
- Choosing not to pursue IVF and considering other family-building options.
Practical questions to ask a clinic in Thailand
When comparing clinics, ask consistent questions so you can compare answers:
- Does the clinic work with a genetics laboratory experienced in PGT-M for my specific mutation?
- How long does test design and validation take before an IVF cycle can start?
- What are the cost components: genetic counselling, test design, IVF, biopsy, analysis, embryo storage, and transfer?
- What are the success rates for my age and diagnosis, and how are they measured?
- What happens to embryos that are affected, inconclusive, or unused?
- What documentation or legal requirements apply to me as an international patient?
- Who provides genetic counselling, and in what language?
- What follow-up testing is recommended during pregnancy?
Planning and next steps
If you are researching IVF for genetic disorders in Thailand, a sensible sequence is:
- Speak with a genetic counsellor or clinical geneticist about your specific condition and inheritance pattern.
- Gather your genetic test reports and family history details.
- Ask clinics whether they can build a PGT-M test for your mutation, and how long it takes.
- Request a written cost estimate covering all stages, including storage and follow-up.
- Confirm legal, documentation, and travel requirements with the clinic and relevant authorities.
- Decide whether PGT-M, another approach, or no testing best fits your situation.
For more background, see our PGT in Thailand overview and our guides. If you have a specific question, our FAQ may help.
Frequently asked questions
Can PGT-M guarantee my baby will not inherit the genetic disorder?
No. PGT-M reduces the chance of transferring an embryo with a specific known mutation, but it cannot guarantee a healthy child. It does not detect all genetic conditions, and some disorders can arise from new mutations. Many clinics recommend confirmatory testing during pregnancy.
Is PGT-M suitable for everyone with a family history of genetic disease?
Not necessarily. Suitability depends on the specific gene, mutation, inheritance pattern, and whether a reliable laboratory test can be built. A genetic counsellor or clinical geneticist can advise whether PGT-M is an option for your situation.
How long does the PGT-M process take in Thailand?
Timelines vary. Test design and validation can take weeks or months before an IVF cycle begins, and results after biopsy may take several days to a couple of weeks. Ask your clinic for a realistic timeline for your specific mutation.
What should I ask a clinic about PGT-M costs?
Ask for a written breakdown covering genetic counselling, test design and validation, IVF cycle, embryo biopsy, genetic analysis, embryo storage, and transfer. Costs vary, so compare itemised estimates rather than single totals.
What happens to embryos that are affected or inconclusive?
Policies vary. Some clinics store them, some may offer transfer after counselling, and some have specific disposal or donation rules. Ask your clinic about its policy and any legal requirements before you start treatment.
Continue your research
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.