At a glance
Deciding how many embryos to biopsy for PGT involves balancing cost, accuracy, and the chance of having a transferable embryo. This guide explains key considerations, including testing all vs. selecting top-quality, and mosaic embryo nuances.
How Many Embryos Should You Test?
There is no single answer that fits every patient. The number of embryos you choose to biopsy for preimplantation genetic testing (PGT) depends on your specific goals, the number of embryos you have, your budget, and your clinic’s recommendations. This article helps you understand the trade-offs so you can make an informed decision with your doctor.
Testing All Embryos vs. Selecting Top-Quality
Testing All Available Embryos
Some patients choose to biopsy every embryo that reaches the blastocyst stage (typically day 5 or 6). The main advantage is that you get complete genetic information on all embryos, which can help you prioritize transfers and avoid transferring an embryo with a chromosomal abnormality. However, this approach costs more (PGT adds a fee per embryo) and may reveal results that lead to discarding embryos that might have self-corrected or resulted in a healthy baby if transferred untested.
Selecting Top-Quality Embryos for Testing
Other patients opt to test only the highest-grade embryos based on morphology (appearance under the microscope). The rationale is that top-quality embryos are more likely to be chromosomally normal, so testing them may give you a good chance of finding a transferable embryo while saving money. The downside is that you might miss a normal embryo that looks lower grade, or you might test a top-quality embryo that turns out to be abnormal, leaving you with fewer options.
Mosaic Embryo Considerations
PGT can identify mosaic embryos—those with a mix of normal and abnormal cells. Mosaic embryos may still have the potential to develop into a healthy baby, but the risk of chromosomal issues is higher than with a fully normal embryo. If you test all embryos, you may discover mosaicism that you would not have known about otherwise. This can complicate decision-making: some clinics recommend transferring mosaic embryos only if no normal embryos are available, while others have specific guidelines. Discuss your clinic’s policy on mosaic embryo transfer and whether they offer additional testing (like PGT-A with next-generation sequencing) to better characterize mosaicism.
Cost-Benefit Analysis
PGT adds a significant cost to IVF. Testing more embryos increases the total expense, but it may also increase the chance of selecting a euploid (normal) embryo for transfer, potentially reducing the number of failed transfers and the emotional and financial toll of repeated cycles. On the other hand, if you have many embryos, testing all of them might not be necessary if you only need one or two normal embryos for your family-building goals. Consider:
- Your family size goal: If you want only one child, you may need fewer tested embryos than if you plan for multiple children.
- Your age and fertility history: Younger patients tend to have higher rates of euploid embryos, so testing fewer may still yield a normal embryo. Older patients or those with recurrent miscarriage may benefit from testing more embryos to avoid transferring abnormal ones.
- Your budget: Some clinics offer package pricing for PGT that covers a certain number of embryos. Ask about discounts for testing multiple embryos.
Questions to Ask Your Clinic
Before deciding, ask your fertility clinic in Thailand:
- What is the cost per embryo for PGT? Are there package deals?
- What is your lab’s biopsy success rate? How many cells are taken?
- How do you report mosaicism? What are your recommendations for mosaic embryo transfer?
- Do you recommend testing all blastocysts or only those with good morphology? Why?
- What is the turnaround time for results? How does that affect fresh vs. frozen transfer?
- Can embryos be re-biopsied if the first test fails?
Related Reading
For more information, see our FAQ on PGT, our guides to IVF in Thailand, and contact us for personalized assistance.
Frequently asked questions
Should I test all my embryos or only the best-looking ones?
There is no right answer for everyone. Testing all embryos gives you complete genetic information but costs more. Testing only top-quality embryos saves money but may miss a normal lower-grade embryo. Discuss with your doctor based on your embryo count, age, and budget.
What is a mosaic embryo, and how does it affect my decision?
A mosaic embryo has both normal and abnormal cells. It may still lead to a healthy baby, but with higher risk. If you test all embryos, you may discover mosaicism, which can complicate transfer decisions. Ask your clinic about their policy on mosaic embryos.
How many embryos do I need to test to have a good chance of pregnancy?
The number varies by age and embryo quality. Younger patients may need fewer tested embryos because they have higher rates of normal embryos. Your doctor can estimate based on your specific situation. There is no guaranteed number.
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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.
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