At a glance
PGT-A screens embryos for chromosomal abnormalities before transfer. Learn how it works, what results mean, and what to ask a Thai IVF clinic before testing.
What is PGT-A?
PGT-A (preimplantation genetic testing for aneuploidy) is a test performed on embryos created through IVF. It checks for the correct number of chromosomes. Embryos with the usual 46 chromosomes are called euploid; those with missing or extra chromosomes are aneuploid. Aneuploidy is a common cause of failed implantation and miscarriage.
PGT-A does not test for every genetic condition. It focuses on chromosomal number, not specific gene mutations. For single-gene disorders, a different test called PGT-M is used.
How PGT-A Works
PGT-A is performed in three main steps:
- Embryo biopsy: A few cells are removed from a day-5 or day-6 embryo (blastocyst stage). The biopsy is usually done on the trophectoderm, which becomes the placenta.
- Genetic analysis: The cells are sent to a genetics laboratory. Techniques such as next-generation sequencing (NGS) are commonly used to count chromosomes.
- Transfer decision: Based on results, a euploid embryo can be selected for transfer. Aneuploid embryos are generally not transferred, though some may be re-tested or discussed with a genetic counselor.
The biopsy is performed by an embryologist, and the analysis is done in a separate genetics lab. The entire process adds time to an IVF cycle because embryos must be frozen while waiting for results.
What PGT-A Results Mean
Results are typically reported as:
- Euploid: normal chromosome number, suitable for transfer.
- Aneuploid: abnormal chromosome number, not usually transferred.
- Mosaic: a mix of normal and abnormal cells. Mosaic embryos may have reduced implantation potential, but some can lead to healthy births. Decisions are made on a case-by-case basis.
- No result: sometimes the biopsy or analysis fails, and no result is obtained.
PGT-A is not a guarantee of a healthy baby. It reduces the risk of chromosomal abnormalities but does not eliminate all risks.
Who Might Consider PGT-A
PGT-A may be considered in several situations:
- Advanced maternal age (usually over 35)
- Previous miscarriage or failed IVF cycles
- Severe male factor infertility
- Known chromosomal translocation in either partner
- Previous pregnancy with a chromosomal abnormality
However, PGT-A is not necessary for everyone. Younger women with no known risks may not benefit significantly. Your doctor can help you weigh the potential advantages and limitations.
PGT-A in Thailand: What to Consider
Thailand has many IVF clinics that offer PGT-A. When researching, consider the following:
- Lab accreditation: Ask if the genetics laboratory is accredited by an international body, such as CAP or ISO.
- Experience: Inquire about the lab’s volume of PGT-A cases and their experience with embryo biopsy.
- Turnaround time: Results may take several days to a few weeks. Ask for the expected timeline.
- Reporting: Ask how results are reported and whether you will receive a detailed report.
- Counseling: Check if genetic counseling is available to help interpret results.
Costs for PGT-A in Thailand vary widely. The price typically includes the biopsy, genetic analysis, and sometimes the initial consultation. Always ask for a detailed breakdown and confirm what is included.
Questions to Ask Your Clinic
Before proceeding with PGT-A, ask your clinic:
- What is your experience with PGT-A?
- Which genetic laboratory do you use, and is it accredited?
- How many cells are biopsied, and what is the success rate of getting a result?
- How long will it take to receive results?
- How are mosaic embryos handled?
- What is the total cost, and what does it include?
- Is genetic counseling available?
Alternatives to PGT-A
PGT-A is one option, but not the only one. Alternatives include:
- IVF without PGT-A: Embryos are selected based on morphology (appearance) alone.
- Non-invasive PGT (niPGT): A newer approach that analyzes DNA in the culture medium, but it is less established.
- Prenatal testing: After pregnancy, tests like NIPT or amniocentesis can check for chromosomal abnormalities.
Discuss these options with your doctor to make an informed choice.
Next Steps
If you are considering PGT-A in Thailand, start by:
- Researching clinics and their PGT-A services.
- Preparing a list of questions from this guide.
- Scheduling a consultation to discuss your specific situation.
- Confirming all costs and timelines in writing.
For more information, explore our PGT in Thailand guide, browse other guides, or check our FAQ section.
Frequently asked questions
Is PGT-A the same as PGT-M?
No. PGT-A screens for chromosomal number abnormalities (aneuploidy), while PGT-M tests for specific single-gene disorders. They are different tests used for different purposes.
Does PGT-A guarantee a healthy baby?
No. PGT-A reduces the risk of chromosomal abnormalities but does not eliminate all risks. It does not test for all genetic conditions, and other factors can affect pregnancy outcome.
How long does PGT-A take in Thailand?
The timeline varies by clinic and laboratory. Typically, results may take several days to a few weeks. Ask your clinic for their specific turnaround time.
What is a mosaic embryo?
A mosaic embryo has a mix of normal and abnormal cells. It may have reduced implantation potential, but some mosaic embryos can lead to healthy births. Decisions are made on a case-by-case basis with genetic counseling.
Is PGT-A necessary for all IVF patients?
No. PGT-A is not necessary for everyone. It may be recommended for certain situations, such as advanced maternal age or recurrent miscarriage. Your doctor can help you decide if it is right for you.
Continue your research
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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