At a glance
Understand the differences between PGT-A and PGT-M, their purposes, processes, and how to decide which test is right for your genetic situation when considering IVF in Thailand.
If you are planning IVF in Thailand and have concerns about genetic conditions, you may be considering preimplantation genetic testing (PGT). Two common types are PGT-A (for aneuploidy) and PGT-M (for monogenic disorders). This article explains the differences, helps you understand which test may apply to your situation, and provides questions to discuss with your fertility clinic.
What Is PGT-A?
PGT-A (preimplantation genetic testing for aneuploidy) screens embryos for an abnormal number of chromosomes. Aneuploidy is a leading cause of implantation failure, miscarriage, and conditions such as Down syndrome. PGT-A is often recommended for women of advanced maternal age (typically over 35), couples with recurrent pregnancy loss, or those with repeated IVF failure. It does not detect specific single-gene disorders.
What Is PGT-M?
PGT-M (preimplantation genetic testing for monogenic disorders) looks for specific inherited genetic conditions caused by a single gene mutation, such as cystic fibrosis, sickle cell disease, or Huntington’s disease. It is used when one or both partners are known carriers of a genetic disorder. PGT-M requires a customized test developed for the family’s specific mutation, which takes additional time and planning.
Key Differences Between PGT-A and PGT-M
| Feature | PGT-A | PGT-M |
|---|---|---|
| Purpose | Screen for chromosome number abnormalities | Detect specific single-gene disorders |
| Who needs it | Advanced maternal age, recurrent miscarriage, repeated IVF failure | Known carriers of a genetic condition, family history of monogenic disease |
| Test development | Standardized protocol, no customization needed | Requires custom probe or test for the specific mutation |
| Timeline | Results in 1–2 weeks after biopsy | Test development may take weeks to months before embryo biopsy |
| Cost | Varies by clinic; confirm directly | Typically higher due to customization; confirm directly |
Can You Have Both PGT-A and PGT-M?
Yes. Many clinics offer combined testing, where embryos are screened for both aneuploidy and a specific monogenic condition. This can reduce the number of embryos that need to be biopsied and provides more comprehensive information. However, combined testing may increase cost and requires coordination between the PGT-A and PGT-M laboratories.
How to Decide Which Test Is Right for You
Step 1: Assess Your Genetic Risk
If you have no known genetic condition but are concerned about age-related chromosome abnormalities, PGT-A may be appropriate. If you or your partner are carriers of a monogenic disorder, PGT-M is necessary to avoid passing it on.
Step 2: Consult with a Genetic Counselor
A genetic counselor can review your family history, recommend carrier screening if not already done, and help interpret test results. Many Thai IVF clinics offer genetic counseling as part of the PGT process.
Step 3: Discuss with Your Fertility Clinic
Ask your clinic about their experience with PGT-A and PGT-M, turnaround times, success rates (note: clinics may not provide specific figures), and whether they offer combined testing. Also inquire about the biopsy technique and embryo freezing protocols.
Questions to Ask Your Clinic
- Do you offer both PGT-A and PGT-M? Are they performed in-house or sent to an external lab?
- How long does it take to develop a custom PGT-M test for our specific mutation?
- What is the estimated timeline from egg retrieval to embryo transfer with PGT?
- What are the costs for PGT-A, PGT-M, and combined testing? Are there any additional fees for biopsy or freezing?
- How many embryos typically survive biopsy and freezing? What is the risk of damage?
- Do you provide genetic counseling before and after testing?
Limitations and Considerations
PGT-A and PGT-M are screening tools, not guarantees. A normal result does not ensure a healthy baby, and an abnormal result does not always mean the embryo is nonviable. Mosaicism (a mix of normal and abnormal cells) can occur, and interpretation may vary. Additionally, PGT-M can only test for the specific mutation requested; it does not screen for other genetic conditions. Discuss the limitations thoroughly with your clinic and genetic counselor.
Next Steps
- Complete carrier screening if not already done.
- Schedule a consultation with a fertility clinic in Thailand that offers PGT.
- Ask about the need for a custom PGT-M test and the timeline.
- Review costs and plan your budget accordingly.
- Consider a genetic counseling session to clarify your options.
For more information, see our PGT in Thailand guide, other guides, and FAQ.
Frequently asked questions
Is PGT-A or PGT-M more expensive?
PGT-M is generally more expensive because it requires a customized test for the specific genetic mutation. PGT-A uses a standardized protocol and is typically less costly. Exact prices vary by clinic and should be confirmed directly.
Can PGT-A detect genetic disorders like cystic fibrosis?
No, PGT-A only screens for chromosome number abnormalities (aneuploidy). It does not detect single-gene disorders. For conditions like cystic fibrosis, PGT-M is required.
Do I need both PGT-A and PGT-M?
It depends on your situation. If you are a carrier of a monogenic disorder and also have risk factors for aneuploidy (e.g., advanced maternal age), combined testing may be recommended. Discuss with your clinic and genetic counselor.
How long does it take to get PGT results?
PGT-A results typically take 1–2 weeks after embryo biopsy. PGT-M may take longer because the custom test must be developed first, which can add weeks or months to the timeline. Confirm with your clinic.
Is PGT guaranteed to produce a healthy baby?
No. PGT is a screening tool that reduces the risk of transferring embryos with certain genetic abnormalities, but it cannot guarantee a healthy pregnancy or baby. Other factors, such as uterine environment and overall embryo health, also play a role.
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.
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