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

What Is Preimplantation Genetic Testing (PGT)?

Preimplantation genetic testing (PGT) is a procedure used during in vitro fertilization (IVF) to screen embryos for genetic abnormalities before transfer to the uterus. PGT is not a guarantee of a healthy pregnancy or live birth, and it is not necessary for every patient. It is a tool that can help some individuals and couples make more informed decisions about which embryos to transfer.

There are three main types of PGT: PGT-A, PGT-M, and PGT-SR. Each type looks for different genetic conditions, and the choice depends on your medical history and family planning goals.

PGT-A (Aneuploidy Screening)

What It Detects

PGT-A screens embryos for aneuploidy—an abnormal number of chromosomes. Humans typically have 46 chromosomes (23 pairs). Having an extra or missing chromosome can cause implantation failure, miscarriage, or conditions such as Down syndrome (trisomy 21).

Who Might Consider PGT-A

• Women of advanced maternal age (typically 35 and older)
• Couples with a history of recurrent miscarriage
• Couples with repeated IVF implantation failure
• Individuals with a known chromosomal abnormality in themselves or a partner

How It Works

After embryos are created through IVF and develop to the blastocyst stage (usually day 5 or 6), a few cells are removed from the trophectoderm (the outer layer that becomes the placenta). These cells are analyzed using techniques such as next-generation sequencing (NGS) to count the chromosomes. Embryos with the correct number of chromosomes (euploid) are prioritized for transfer.

Limitations

• PGT-A cannot detect all genetic disorders, only chromosomal number abnormalities.
• There is a small risk of a false positive or false negative result.
• Some embryos may be mosaic (having both normal and abnormal cells), which complicates interpretation.
• PGT-A does not guarantee implantation or a healthy baby.

PGT-M (Monogenic Disorders)

What It Detects

PGT-M screens for specific single-gene disorders (monogenic diseases) such as cystic fibrosis, sickle cell disease, Tay-Sachs disease, or Huntington’s disease. It is used when one or both parents carry a known genetic mutation that could be passed to their children.

Who Might Consider PGT-M

• Couples where one or both partners have a known genetic disorder
• Carriers of autosomal recessive or dominant conditions
• Couples with a family history of a specific genetic disease
• Individuals who want to avoid passing on a serious inherited condition

How It Works

PGT-M requires a customized test for each family. Before the IVF cycle, the genetic mutation must be identified, and a test is developed using DNA samples from the parents and sometimes other family members. During the IVF cycle, embryos are biopsied similarly to PGT-A, and the cells are analyzed for the specific mutation. Only embryos without the mutation are considered for transfer.

Limitations

• PGT-M is only available for known genetic mutations; it cannot screen for unknown or new mutations.
• Test development can take weeks to months and adds to the overall timeline and cost.
• PGT-M does not screen for chromosomal abnormalities unless combined with PGT-A.
• Not all genetic disorders can be tested due to technical limitations.

PGT-SR (Structural Rearrangements)

What It Detects

PGT-SR screens for structural chromosomal rearrangements, such as translocations (where a piece of one chromosome attaches to another) or inversions (where a chromosome segment is reversed). These rearrangements can lead to unbalanced chromosomes in embryos, increasing the risk of miscarriage or birth defects.

Who Might Consider PGT-SR

• Individuals or couples where one partner carries a balanced translocation or inversion
• Couples with a history of recurrent miscarriage due to chromosomal rearrangements
• Those with a known structural abnormality in their karyotype

How It Works

PGT-SR uses similar biopsy and analysis techniques as PGT-A, but the focus is on identifying embryos with unbalanced chromosomal rearrangements. The test can determine whether an embryo has inherited a balanced or unbalanced set of chromosomes. Only embryos with normal or balanced chromosomes are considered for transfer.

Limitations

• PGT-SR cannot detect all types of structural rearrangements; some may be too small to identify.
• It may not distinguish between a balanced translocation and a completely normal chromosome arrangement.
• PGT-SR does not screen for single-gene disorders unless combined with PGT-M.

Key Differences at a Glance

Can PGT Types Be Combined?

Yes, it is possible to combine PGT-A with PGT-M or PGT-SR in a single biopsy. For example, a couple who carries a genetic mutation and also wants to screen for aneuploidy can request both tests. This approach provides more comprehensive information but may increase the cost and complexity of the testing process.

PGT in Thai IVF Clinics

Many IVF centers in Thailand offer PGT services, including PGT-A, PGT-M, and PGT-SR. For instance, Deep & Harmonicare IVF Center (DHC) provides PGT as part of its IVF services. DHC holds multiple international accreditations, including JCI, ISO 9001, RTAC, CAP, and UK NEQAS, which reflect quality standards in laboratory and clinical practices. Other clinics, such as Bumrungrad International Hospital, also offer reproductive medicine services, including IVF and genetic testing. However, the specific availability of PGT types, turnaround times, and costs vary by clinic. Patients should confirm directly with the clinic which PGT options are available and whether they require additional genetic counseling or test development.

When considering PGT in Thailand, it is important to ask the clinic about:

• Which types of PGT are offered (PGT-A, PGT-M, PGT-SR)
• Whether combined testing is possible
• The laboratory’s accreditation and experience with genetic testing
• Turnaround time for results (typically 1–2 weeks)
• Costs for each type of PGT and any additional fees for test customization
• How mosaic embryos are reported and managed

Alternatives to PGT

PGT is not the only option for genetic screening. Alternatives include:

• Prenatal testing (chorionic villus sampling or amniocentesis) during pregnancy to diagnose genetic conditions.
• Non-invasive prenatal testing (NIPT) to screen for common chromosomal abnormalities during pregnancy.
• Carrier screening before conception to identify if parents carry mutations for certain genetic disorders.
• Donor eggs or sperm from screened donors to reduce the risk of inherited conditions.

Each option has its own benefits and limitations. Discuss with your fertility specialist and genetic counselor to determine the best approach for your situation.

Frequently Asked Questions

Is PGT mandatory for IVF in Thailand?

No, PGT is not mandatory. It is an optional test that may be recommended based on your medical history and family planning goals. Some patients may not need PGT at all.

Does PGT guarantee a healthy baby?

No. PGT reduces the risk of transferring embryos with certain genetic abnormalities, but it cannot guarantee implantation, a successful pregnancy, or a healthy child. Other factors, such as uterine environment and overall embryo quality, also play important roles.

How long does PGT take?

After embryo biopsy, results typically take 1–2 weeks. For PGT-M, additional time is needed for test development before the IVF cycle begins.

Can PGT be done on frozen embryos?

Yes, PGT can be performed on embryos that have been frozen and thawed, but the biopsy is usually done before freezing. Some clinics may offer re-biopsy of frozen embryos, but this is less common and may have lower success rates.

What is the cost of PGT in Thailand?

Costs vary widely by clinic and the type of PGT. For example, DHC’s basic single-cycle medical package is priced at THB 490,000 (as of June 2026), but this does not include PGT fees. Patients should request a detailed quotation that includes all genetic testing costs.

Next Steps

If you are considering PGT as part of your IVF journey in Thailand, start by consulting with a fertility specialist and a genetic counselor. They can help you understand which type of PGT, if any, is appropriate for your situation. For more information, explore our PGT in Thailand guide and other resources. You can also check our FAQ page for common questions.

Frequently asked questions

Is PGT mandatory for IVF in Thailand?

No, PGT is not mandatory. It is an optional test that may be recommended based on your medical history and family planning goals. Some patients may not need PGT at all.

Does PGT guarantee a healthy baby?

No. PGT reduces the risk of transferring embryos with certain genetic abnormalities, but it cannot guarantee implantation, a successful pregnancy, or a healthy child. Other factors, such as uterine environment and overall embryo quality, also play important roles.

How long does PGT take?

After embryo biopsy, results typically take 1–2 weeks. For PGT-M, additional time is needed for test development before the IVF cycle begins.

Can PGT be done on frozen embryos?

Yes, PGT can be performed on embryos that have been frozen and thawed, but the biopsy is usually done before freezing. Some clinics may offer re-biopsy of frozen embryos, but this is less common and may have lower success rates.

What is the cost of PGT in Thailand?

Costs vary widely by clinic and the type of PGT. For example, DHC's basic single-cycle medical package is priced at THB 490,000 (as of June 2026), but this does not include PGT fees. Patients should request a detailed quotation that includes all genetic testing costs.

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.