Understanding PGT-A Biopsy Timing in Thailand: What to Expect

If you are considering preimplantation genetic testing for aneuploidy (PGT-A) as part of your IVF journey in Thailand, one of the most common questions is: when does the biopsy actually happen? The answer is usually on day 5 or day 6 after fertilization, when the embryo has reached the blastocyst stage. This timing is important because it allows the embryologist to safely remove a few cells from the trophectoderm, the part that will become the placenta, without harming the inner cell mass that will form the fetus.

In this guide, we explain the typical timing of PGT-A biopsy, what the process involves, and what you should ask your clinic to feel confident about the embryology lab handling your embryos.

At a Glance: PGT-A Biopsy Timing

• Biopsy is usually performed on day 5 or day 6 after fertilization.
• Embryos must reach the blastocyst stage before biopsy.
• The embryologist removes 3–5 cells from the trophectoderm.
• The biopsied cells are sent for genetic analysis, while the embryo is frozen.
• Results typically take several days to a few weeks, depending on the lab.

Why Day 5 or Day 6?

Embryos develop in stages. After fertilization, the embryo divides and grows, reaching the blastocyst stage around day 5 or day 6. At this point, the embryo has two distinct cell types: the inner cell mass (which becomes the fetus) and the trophectoderm (which becomes the placenta). Biopsying at this stage allows the embryologist to remove cells from the trophectoderm, which is less likely to affect the embryo’s development compared to earlier stages.

Performing the biopsy earlier, such as on day 3, is possible but less common for PGT-A. Day 3 biopsy involves removing a cell from the cleavage-stage embryo, which may be more invasive. Most clinics in Thailand prefer day 5 or day 6 biopsy because it is safer and provides more cells for analysis.

The PGT-A Biopsy Process in Thailand

The biopsy procedure is performed in an embryology laboratory by a trained embryologist. Here is a step-by-step overview of what typically happens:

1. Embryo culture: After fertilization, embryos are cultured in the lab for about 5 to 6 days until they reach the blastocyst stage.
2. Hatching assistance: The embryologist may use a laser to create a small opening in the zona pellucida, the outer shell of the embryo, to facilitate cell removal.
3. Cell removal: Using a fine pipette, the embryologist gently aspirates 3–5 cells from the trophectoderm.
4. Biopsy sample handling: The removed cells are placed in a tube for genetic analysis.
5. Embryo freezing: After biopsy, the embryo is vitrified (frozen) while awaiting results.
6. Genetic analysis: The biopsied cells are sent to a genetics laboratory for PGT-A testing, which checks for chromosomal abnormalities.

The entire biopsy procedure is delicate and requires precision. The embryologist’s skill and the laboratory’s quality are critical to the safety and accuracy of the process.

What to Expect After the Biopsy

After the biopsy, your embryos will be frozen. This is standard practice because the genetic analysis takes time, and the results are needed before a frozen embryo transfer (FET) can be planned. The freezing process, called vitrification, is well-established and widely used in Thailand.

The time to receive PGT-A results can vary. Some labs may provide results within a few days, while others may take a week or more. Your clinic will give you a timeline based on their specific laboratory arrangements.

Once the results are available, your doctor will discuss which embryos are chromosomally normal (euploid) and suitable for transfer. It is important to remember that PGT-A does not guarantee a pregnancy or a healthy baby; it is a screening tool that can help reduce the risk of miscarriage and certain chromosomal conditions.

Questions to Ask About the Embryology Lab

When choosing a clinic in Thailand for PGT-A, it is essential to ask about the embryology lab’s experience and protocols. Here are some questions to consider:

• How many PGT-A cycles does the lab perform per year?
• What is the embryologist’s experience with blastocyst biopsy?
• Does the lab use laser-assisted hatching for biopsy?
• How many cells are typically removed, and what is the success rate of obtaining a diagnosis?
• What is the lab’s policy on embryo re-biopsy if the first sample is inconclusive?
• How are embryos identified and tracked to avoid mix-ups?
• What is the turnaround time for PGT-A results?
• Is the genetics laboratory accredited or certified?

These questions can help you gauge the quality and reliability of the embryology lab, which is a key factor in the success of PGT-A.

Factors That Can Affect Biopsy Timing

While day 5 or day 6 is the standard, the exact timing can vary based on embryo development. Some embryos may reach the blastocyst stage earlier or later. In some cases, an embryo may not be suitable for biopsy on day 5 and may be observed until day 6 or even day 7. However, not all embryos will reach the blastocyst stage, and some may not be biopsied at all.

Your clinic will monitor embryo development and decide the best time for biopsy. It is important to understand that not every embryo will be suitable for PGT-A, and the number of embryos available for testing can vary.

Next Steps: Planning Your PGT-A Cycle in Thailand

If you are considering PGT-A in Thailand, here is a checklist to help you move forward:

• Research clinics that offer PGT-A and have experience with blastocyst biopsy.
• Schedule a consultation to discuss your medical history and whether PGT-A is appropriate for you.
• Ask about the clinic’s embryology lab and genetics laboratory arrangements.
• Clarify the costs involved, including biopsy, genetic analysis, and embryo freezing.
• Understand the legal and regulatory aspects of PGT-A in Thailand, as they can vary.
• Plan for the timeline, including the biopsy day and the wait for results.

Remember, PGT-A is not a mandatory step for everyone. Your doctor can help you decide if it is right for your situation.

Conclusion

PGT-A biopsy timing in Thailand typically falls on day 5 or day 6 after fertilization, when embryos have reached the blastocyst stage. The process is safe and well-established, but it requires a skilled embryologist and a high-quality lab. By asking the right questions and understanding what to expect, you can approach this step with confidence.

For more information about PGT in Thailand, explore our PGT in Thailand guide, or visit our guides and FAQ sections for additional insights.

Frequently asked questions

Is PGT-A biopsy painful for the embryo?

Embryos do not have a nervous system, so they do not feel pain. The biopsy is performed under a microscope, and the embryologist removes a few cells from the outer layer of the blastocyst. This is a delicate procedure, but it is not painful for the embryo.

Can PGT-A biopsy damage the embryo?

There is a small risk that the biopsy could affect the embryo, but it is generally considered safe when performed by an experienced embryologist. The removal of trophectoderm cells is less likely to harm the embryo than biopsy at earlier stages. However, no procedure is without risk, and your clinic should discuss the potential risks with you.

How long does it take to get PGT-A results in Thailand?

The turnaround time for PGT-A results can vary depending on the genetics laboratory. Some labs may provide results within a few days, while others may take a week or more. Your clinic will give you a specific timeline based on their arrangements.

What happens if the biopsy sample is inconclusive?

In rare cases, the biopsied cells may not yield enough DNA for analysis, leading to an inconclusive result. In such situations, the clinic may offer a re-biopsy of the embryo, but this depends on the embryo's condition and the clinic's policies. It is important to ask about this possibility beforehand.

Does PGT-A guarantee a healthy baby?

No, PGT-A does not guarantee a healthy baby. It is a screening tool that can identify embryos with the correct number of chromosomes, which may reduce the risk of miscarriage and certain chromosomal conditions. However, it does not test for all genetic disorders, and other factors can affect pregnancy outcomes.

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.