PGT-A vs PGT-M in Thailand: What’s the Difference?

PGT-A vs PGT-M: A Quick Overview

If you are exploring IVF in Thailand, you may come across two common genetic tests: PGT-A and PGT-M. Both are performed on embryos created through IVF before a transfer is considered. However, they look for different things and are used in different situations.

PGT-A (Preimplantation Genetic Testing for Aneuploidy) checks embryos for the correct number of chromosomes. PGT-M (Preimplantation Genetic Testing for Monogenic disorders) looks for a specific inherited genetic condition that runs in the family. Understanding the difference can help you have more informed conversations with your fertility team.

At a Glance: PGT-A vs PGT-M

• PGT-A screens for chromosomal abnormalities (aneuploidy) that may affect implantation or lead to miscarriage.
• PGT-M tests for a specific single-gene disorder, such as cystic fibrosis or sickle cell disease, when one or both partners carry the gene.
• PGT-SR (for structural rearrangements) is sometimes mentioned alongside these tests; it checks for balanced or unbalanced chromosomal rearrangements.
• Both tests require IVF and embryo biopsy, usually around day 5 or 6 of development.
• Neither test guarantees a pregnancy or a healthy baby; they are screening tools that provide information.

What Is PGT-A?

PGT-A is designed to detect an abnormal number of chromosomes in an embryo. Humans typically have 46 chromosomes. Having an extra or missing chromosome is called aneuploidy. Many embryos with aneuploidy do not implant, or they may lead to miscarriage. Some chromosomal abnormalities can also result in conditions such as Down syndrome.

PGT-A is often considered for:

• People of advanced maternal age (usually over 35, but exact thresholds vary by clinic).
• Those who have experienced recurrent pregnancy loss.
• Couples with repeated IVF implantation failure.
• People who want to reduce the chance of transferring an embryo with a chromosomal abnormality.

It is important to note that PGT-A does not test for every genetic condition. It only looks at chromosome number, not single-gene disorders.

What Is PGT-M?

PGT-M is used when there is a known single-gene disorder in the family. This test identifies whether an embryo has inherited the specific genetic mutation that causes the condition. Examples include cystic fibrosis, Tay-Sachs disease, and Huntington’s disease, among many others.

PGT-M is typically considered when:

• One or both partners are known carriers of a genetic disorder.
• A couple has a child with a genetic condition.
• There is a family history of a specific inherited disease.

Before PGT-M can be performed, the specific genetic mutation must be identified through prior genetic testing of the parents or an affected family member. This often requires a separate workup before the IVF cycle begins.

Key Differences Between PGT-A and PGT-M

Aspect	PGT-A	PGT-M
Purpose	Checks for abnormal chromosome numbers	Checks for a specific single-gene disorder
Who may consider it	People with age-related concerns, recurrent miscarriage, or repeated implantation failure	Couples with a known genetic condition in the family
Requires prior genetic information?	No, it is a general screen	Yes, the specific mutation must be known
What it can detect	Aneuploidy (e.g., trisomy, monosomy)	Specific inherited disorders like cystic fibrosis or sickle cell disease
What it does not detect	Single-gene disorders, structural rearrangements	Chromosomal abnormalities unrelated to the specific gene

How Are PGT-A and PGT-M Performed in Thailand?

Both tests follow a similar process within an IVF cycle:

1. Ovarian stimulation and egg retrieval – Eggs are collected from the ovaries.
2. Fertilization – Eggs are fertilized with sperm in the laboratory.
3. Embryo culture – Embryos are grown to the blastocyst stage, usually by day 5 or 6.
4. Biopsy – A few cells are removed from the outer layer of the embryo (trophectoderm). This is done by an embryologist.
5. Genetic analysis – The cells are sent to a genetics laboratory for testing. The method may vary (e.g., next-generation sequencing or other techniques).
6. Results and transfer – Once results are available, the fertility team discusses which embryos may be suitable for transfer. Not all embryos may be suitable, and some may be deemed not transferable.

In Thailand, many IVF clinics offer PGT-A and PGT-M, often in partnership with specialized genetic laboratories. The availability and specific protocols can vary, so it is important to ask your clinic about their procedures and timelines.

Cost and Availability in Thailand

The cost of PGT-A and PGT-M in Thailand can vary widely depending on the clinic, the number of embryos tested, and the specific genetic analysis required. PGT-M is often more expensive than PGT-A because it requires a customized test for the specific genetic mutation.

When comparing clinics, consider asking for a detailed breakdown of costs, including:

• The cost of the IVF cycle itself.
• The biopsy fee.
• The genetic analysis fee per embryo.
• Any additional consultations or genetic counseling fees.

Availability may also depend on the clinic’s laboratory partnerships and whether they have experience with the specific genetic condition you are testing for. Some clinics may need to send samples to an external laboratory, which can affect turnaround time.

Which Test Is Right for You?

The choice between PGT-A and PGT-M depends on your medical history and genetic background. There is no one-size-fits-all answer.

• If you have no known genetic disorder in your family but are concerned about chromosomal abnormalities due to age or previous miscarriages, PGT-A may be discussed.
• If you or your partner are carriers of a specific genetic condition, PGT-M may be more relevant.
• In some cases, both tests may be performed together, but this is not always necessary or recommended.

Your fertility specialist and a genetic counselor can help you understand your risks and the potential benefits and limitations of each test. They can also explain what the results might mean for your family-building options.

Limitations and Considerations

It is essential to understand that PGT is not a guarantee of a successful pregnancy or a healthy baby. Here are some limitations to keep in mind:

• Mosaicism – Some embryos may have a mix of normal and abnormal cells. The clinical significance of mosaicism is still being studied.
• Biopsy risks – Although rare, the biopsy procedure carries a small risk of damaging the embryo.
• Test accuracy – No genetic test is 100% accurate. There is a small chance of a false positive or false negative result.
• Not all conditions are tested – PGT-A does not screen for all genetic disorders, and PGT-M only looks for the specific condition it was designed to detect.
• Ethical and legal considerations – The use of PGT may be regulated in some countries. In Thailand, the legal framework may evolve, so it is important to stay informed.

Questions to Ask Your Clinic in Thailand

When you consult with a fertility clinic in Thailand, consider asking these questions:

• What is your experience with PGT-A and PGT-M?
• Do you perform the biopsy in-house, or do you send samples to an external laboratory?
• How long does it take to receive results?
• What is the cost per embryo for each test?
• Do you offer genetic counseling before and after testing?
• How do you handle embryos with uncertain results, such as mosaicism?
• What are the success rates for embryo transfer after PGT in your clinic? (Ask for their own data, not general statistics.)

Next Steps

If you are considering PGT-A or PGT-M in Thailand, here is a simple checklist:

1. Gather your medical records, including any previous genetic testing results.
2. Research clinics that offer the specific test you may need.
3. Schedule a consultation to discuss your history and options.
4. Ask for a detailed cost estimate and timeline.
5. Consider speaking with a genetic counselor to understand the implications of testing.

For more general information about PGT in Thailand, you can visit our PGT in Thailand page. You may also find our guides and FAQ sections helpful as you continue your research.

Frequently asked questions

Can PGT-A and PGT-M be done at the same time?

Yes, in some cases both tests can be performed on the same embryo biopsy. This is often referred to as combined PGT. However, it may not be necessary for everyone. Your clinic can advise whether combined testing is appropriate based on your medical history and genetic risk.

Is PGT-M more expensive than PGT-A in Thailand?

Generally, PGT-M tends to be more expensive than PGT-A because it requires a customized test for a specific genetic mutation. The exact cost varies by clinic and the complexity of the test. It is best to ask your clinic for a detailed quote.

Do I need PGT if I am young and have no known genetic issues?

PGT is not recommended for everyone. Many fertility specialists suggest PGT-A for people with specific risk factors, such as advanced maternal age or recurrent miscarriage. If you have no known genetic disorders, PGT-M is unlikely to be needed. Your doctor can help you decide based on your individual situation.

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

PGT-A screens for an abnormal number of chromosomes (aneuploidy). PGT-SR is used when one parent has a structural rearrangement of chromosomes, such as a translocation. PGT-SR looks for embryos with unbalanced chromosomal rearrangements that could lead to miscarriage or birth defects. Both tests are types of preimplantation genetic testing.

Continue your research

• PGT in Thailand overview
• PGT and IVF guides
• Frequently asked questions

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.