What Is PGT and Why Is It Used in Thailand IVF?

What Is Preimplantation Genetic Testing (PGT)?

Preimplantation genetic testing (PGT) is a procedure used during in vitro fertilization (IVF) to examine embryos for genetic abnormalities before they are transferred to the uterus. PGT is a screening tool that may help select embryos with a lower risk of certain genetic conditions. The decision to use PGT should be made with a fertility specialist and a genetic counselor.

Types of PGT: PGT-A, PGT-M, and PGT-SR

There are three main types of PGT, each designed for different purposes:

PGT-A (Aneuploidy Screening)

PGT-A screens embryos for an abnormal number of chromosomes (aneuploidy). It is often considered for patients of advanced maternal age, those with recurrent pregnancy loss, or repeated IVF failure. However, PGT-A cannot detect all chromosomal abnormalities.

PGT-M (Monogenic Disorders)

PGT-M is used when one or both parents carry a known genetic mutation for a single-gene disorder, such as cystic fibrosis, sickle cell disease, or Huntington’s disease. The test identifies embryos that carry the mutation, allowing the transfer of unaffected embryos. PGT-M requires a customized test for each family, which takes time to develop.

PGT-SR (Structural Rearrangements)

PGT-SR is for individuals who carry balanced chromosomal rearrangements, such as translocations or inversions. These rearrangements may not affect the carrier’s health but can lead to unbalanced chromosomes in embryos. PGT-SR helps identify embryos with a normal or balanced chromosome structure.

How Is PGT Performed?

PGT is performed on embryos created through IVF. After fertilization, embryos are cultured in the laboratory for about 5–6 days until they reach the blastocyst stage. A few cells are then biopsied from the trophectoderm (the part that becomes the placenta) and sent for genetic analysis. The embryos are frozen (vitrified) while awaiting results. The genetic analysis typically takes 1–2 weeks. Once results are available, a chromosomally normal (euploid) or unaffected embryo can be thawed and transferred in a subsequent cycle.

Understanding PGT Results

PGT results are reported as:

• Euploid: The embryo has the expected number of chromosomes (for PGT-A) or does not carry the tested mutation (for PGT-M/SR). These embryos are considered suitable for transfer.
• Aneuploid: The embryo has an abnormal number of chromosomes. These embryos are generally not recommended for transfer, though some clinics may consider mosaic embryos (a mix of normal and abnormal cells) on a case-by-case basis.
• Mosaic: Some cells are normal and some are abnormal. The clinical significance is uncertain, and transfer decisions should be made with genetic counseling.
• Inconclusive: The biopsy sample did not yield a result, often due to technical issues. Retesting may be possible.

It is essential to understand that PGT is a screening test, not a diagnostic test. A normal result reduces but does not eliminate the risk of a genetic condition. Confirmatory prenatal testing (e.g., chorionic villus sampling or amniocentesis) is recommended after pregnancy is achieved.

Who Might Consider PGT?

PGT may be considered in the following situations:

• Women of advanced maternal age (typically 35 or older)
• Couples with a known genetic disorder
• Couples with recurrent pregnancy loss
• Couples with repeated IVF failure
• Individuals with a balanced chromosomal rearrangement
• Couples seeking to avoid passing on a sex-linked genetic disorder (though PGT for sex selection for non-medical reasons is not permitted in many countries, including Thailand)

PGT is not recommended for everyone. It adds cost, time, and complexity to IVF. Some patients may achieve pregnancy without PGT. A fertility specialist can help determine if PGT is appropriate based on individual medical history.

Alternatives to PGT

Alternatives to PGT include:

• Prenatal diagnosis: Testing during pregnancy (e.g., amniocentesis) to diagnose genetic conditions. This does not avoid the need for possible termination.
• Donor gametes: Using donor eggs or sperm from a screened donor to reduce genetic risk.
• Natural conception with genetic counseling: Accepting the risk and undergoing prenatal testing if pregnancy occurs.

Each option has benefits and limitations. A genetic counselor can help patients weigh their choices.

Limitations of PGT

PGT has several limitations:

• It cannot detect all genetic disorders or chromosomal abnormalities.
• It does not guarantee implantation, pregnancy, or a live birth.
• There is a small risk of embryo damage from biopsy.
• Mosaic results can be difficult to interpret.
• PGT-M requires a customized test that may take weeks to develop.
• Cost can be significant and is often not covered by insurance.

Why Do Patients Choose Thailand for PGT?

Thailand has become a popular destination for IVF with PGT for several reasons:

• Cost: PGT in Thailand is generally more affordable than in many Western countries. For example, Deep & Harmonicare IVF Center (DHC) offers a basic single-cycle medical package at a reference price of THB 490,000. Final costs vary by medication, testing, storage, procedures, and travel.
• Legal framework: Thailand has clear regulations that permit PGT for medical reasons, including PGT-A, PGT-M, and PGT-SR. Sex selection for non-medical reasons is prohibited. The legal environment provides certainty for international patients.
• Quality of care: Many Thai fertility centers hold international accreditations. For instance, DHC holds JCI, ISO 9001, RTAC, CAP, and UK NEQAS certifications. Bumrungrad International Hospital is a large multidisciplinary hospital with integrated services. Prime Fertility Clinic has JCI Ambulatory Care accreditation. Patients should verify current credentials directly.
• Experienced specialists: Thailand has reproductive medicine specialists with training in genetics. For example, Dr. Phattaraphum Phophong at Bumrungrad has training in reproductive medicine and prenatal genetics. Dr. Waranya Sirithanasarn at Gift Fertility Clinic has 13 years of experience. Dr. Poonkiat Punyamitr at Prime Fertility Clinic has 19 years of experience. Confirm the treating doctor and their expertise.
• Advanced technology: Some clinics use time-lapse incubators (e.g., Embryoscope+, Geri) and other technologies to support embryo culture. However, technology alone does not guarantee success.

It is important to note that no clinic can guarantee a specific outcome. Success rates vary by individual factors. Patients should request a written quotation and confirm all services included.

Choosing a Clinic in Thailand for PGT

When selecting a clinic for PGT in Thailand, consider the following:

• Does the clinic have a dedicated genetic testing laboratory or partnership with a reputable lab?
• What types of PGT are offered (PGT-A, PGT-M, PGT-SR)?
• What are the costs for the IVF cycle, PGT, biopsy, freezing, and storage?
• What is the experience of the embryology team?
• Does the clinic provide genetic counseling?
• What are the clinic’s success rates for your age group and diagnosis? (Be cautious of self-reported rates; ask for independent verification.)

For a comparison of clinics, see our PGT in Thailand guide and other guides. For common questions, visit our FAQ page.

Conclusion

PGT is a valuable tool for some patients undergoing IVF, but it is not a guarantee of success. Understanding the types of PGT, what results mean, and the limitations is essential. Thailand offers a combination of affordable cost, legal clarity, and quality care that attracts international patients. However, each patient’s situation is unique. Consult with a fertility specialist and genetic counselor to determine if PGT is right for you.

Frequently asked questions

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

PGT-A screens for an abnormal number of chromosomes (aneuploidy). PGT-M tests for specific single-gene disorders when parents carry a known mutation. PGT-SR checks for unbalanced chromosomes due to structural rearrangements like translocations.

Does PGT guarantee a healthy baby?

No. PGT is a screening test that reduces the risk of certain genetic conditions but cannot detect all abnormalities. It does not guarantee implantation, pregnancy, or a live birth. Confirmatory prenatal testing is recommended.

Is PGT legal in Thailand?

Yes, PGT for medical reasons is permitted in Thailand. Sex selection for non-medical reasons is prohibited. Patients should confirm the legal framework with their chosen clinic.

How much does PGT cost in Thailand?

Costs vary by clinic and individual treatment plan. For example, Deep & Harmonicare IVF Center (DHC) offers a basic single-cycle medical package at a reference price of THB 490,000. Final costs depend on medication, testing, storage, and other factors. Always request a written quotation.

Who should consider PGT?

PGT may be considered for women of advanced maternal age, couples with known genetic disorders, those with recurrent pregnancy loss or repeated IVF failure, and individuals with balanced chromosomal rearrangements. It is not recommended for everyone. Consult a fertility specialist.

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.