How Does PGT Work in Thailand IVF? A Step-by-Step Guide

What Is PGT and Why Is It Used in IVF?

Preimplantation genetic testing (PGT) is a screening tool used during in vitro fertilization (IVF) to analyze embryos for genetic abnormalities before transfer. It is not a treatment or a guarantee of pregnancy or a healthy child. PGT helps fertility specialists and patients make more informed decisions about which embryos to transfer, potentially reducing the risk of certain genetic disorders or chromosomal issues.

In Thailand, PGT is available at several fertility centers and hospitals. The process involves three main steps: embryo biopsy, genetic analysis, and result interpretation to guide transfer decisions.

Step 1: Embryo Biopsy

After egg retrieval and fertilization (usually via ICSI), embryos are cultured in the laboratory for about 5–6 days until they reach the blastocyst stage. At this stage, the embryo has two distinct cell types: the inner cell mass (which becomes the fetus) and the trophectoderm (which becomes the placenta).

A skilled embryologist uses a laser to create a small opening in the zona pellucida (the outer shell of the embryo) and gently removes 3–5 trophectoderm cells. This is called a trophectoderm biopsy. The biopsied cells are sent for genetic analysis, while the embryo is frozen (vitrified) to await results.

Biopsy is a delicate procedure. While studies show it is generally safe, there is a small risk of damage to the embryo. Not all embryos survive the biopsy and freezing process.

Step 2: Genetic Analysis

The biopsied cells are analyzed in a genetics laboratory using one of several techniques, depending on the type of PGT being performed:

• PGT-A (Aneuploidy): Screens for the correct number of chromosomes. Embryos with too many or too few chromosomes (aneuploid) often fail to implant or miscarry. PGT-A can identify embryos with a normal chromosome count (euploid).
• PGT-M (Monogenic): Tests for specific single-gene disorders such as cystic fibrosis, thalassemia, or Huntington’s disease. This requires prior knowledge of the genetic mutation in the family.
• PGT-SR (Structural Rearrangement): Detects unbalanced chromosomal rearrangements, such as translocations, which can cause implantation failure or miscarriage.

Analysis typically takes 1–2 weeks. Results are reported as:

• Euploid: Normal chromosome number (for PGT-A) or unaffected (for PGT-M/SR).
• Aneuploid: Abnormal chromosome number.
• Mosaic: A mix of normal and abnormal cells in the biopsied sample. Mosaic embryos may still have potential for a healthy pregnancy, but the outcome is less predictable.
• Inconclusive: The sample could not be analyzed, often due to insufficient or degraded DNA.

Step 3: Result Interpretation and Transfer Decision

Your fertility specialist will discuss the results with you. Euploid embryos are typically prioritized for transfer. Aneuploid embryos are usually not transferred, though some patients may consider transfer in exceptional circumstances after thorough counseling. Mosaic embryos require careful discussion of risks and benefits.

PGT results are not 100% accurate. There is a small chance of a false positive or false negative. Additionally, PGT cannot detect all genetic conditions, and a normal result does not guarantee a healthy baby.

Types of PGT: Which One Is Right for You?

Not all patients need PGT. Your doctor may recommend it based on:

• Maternal age (advanced maternal age increases risk of aneuploidy)
• Recurrent pregnancy loss or implantation failure
• Known genetic disorder in the family
• Severe male factor infertility
• Previous pregnancy with a chromosomal abnormality

PGT-A is the most common type. PGT-M and PGT-SR are used for specific genetic indications. Some patients may choose not to test and rely on embryo morphology (appearance) alone.

Alternatives to PGT

PGT is not the only option. Alternatives include:

• Morphological assessment: Selecting embryos based on their appearance under a microscope. This is less precise but avoids the cost and risk of biopsy.
• Preimplantation genetic screening without biopsy: Experimental techniques like spent culture medium analysis are not yet standard practice.
• Prenatal testing: Chorionic villus sampling (CVS) or amniocentesis during pregnancy can diagnose genetic conditions, but these tests occur after implantation.

Limitations of PGT

It is essential to understand what PGT cannot do:

• It does not guarantee pregnancy, live birth, or a healthy child.
• It cannot detect all genetic disorders or birth defects.
• Biopsy may harm the embryo in rare cases.
• Mosaic results can be difficult to interpret.
• PGT is an additional cost (typically THB 50,000–100,000 or more per cycle in Thailand, but confirm with your clinic).

PGT in Thailand: What to Expect

Thailand has several fertility centers offering PGT, including dedicated IVF clinics and multidisciplinary hospitals. The process is similar to other countries, but you should verify:

• The laboratory’s accreditation and experience with PGT.
• Whether the center uses next-generation sequencing (NGS) or other platforms.
• Costs for biopsy, analysis, and embryo freezing.
• Legal considerations: Thailand’s regulations on PGT are generally permissive, but confirm with your clinic regarding PGT-M for non-medical sex selection or other uses.

For more details, see our PGT in Thailand guide and other resources. Common questions are answered in our FAQ.

Key Takeaways

• PGT is a screening tool, not a guarantee.
• The process involves embryo biopsy, genetic analysis, and result-based transfer decisions.
• PGT-A, PGT-M, and PGT-SR serve different purposes.
• Discuss risks, benefits, and alternatives with your fertility specialist.
• Confirm all details directly with your chosen clinic in Thailand.

Frequently asked questions

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

PGT-A screens for the correct number of chromosomes (aneuploidy). PGT-M tests for specific single-gene disorders. PGT-SR detects unbalanced chromosomal rearrangements. Each type is used for different indications.

Is PGT mandatory for IVF in Thailand?

No, PGT is optional. It is recommended for certain medical indications but not required for all patients. You can choose to transfer embryos based on morphology alone.

How long does PGT take in Thailand?

After embryo biopsy, genetic analysis typically takes 1–2 weeks. Embryos are frozen during this time. The entire IVF cycle with PGT may take 6–8 weeks from start to transfer.

Can PGT guarantee a healthy baby?

No. PGT reduces the risk of certain genetic conditions but cannot detect all disorders. There is also a small chance of error. A normal PGT result does not guarantee a healthy pregnancy or child.

What are the risks of embryo biopsy?

Risks include potential damage to the embryo, reduced viability, and inconclusive results. However, with experienced embryologists, the risk is low. Discuss with your clinic.

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.