Reviewed by the Genesis Fertility Center (GFC) medical team — Last updated June 2026
In embryo chromosome screening (PGT-A), the term “NGS” comes up frequently. Many people wonder what NGS is and why it matters for testing accuracy.
This article explains NGS clearly, so you understand the technology behind embryo testing.
What Is NGS?
NGS (Next Generation Sequencing) is a modern, high-accuracy technology for reading genetic sequences. It can comprehensively examine chromosome number and abnormalities in fine detail.
In IVF, NGS is used in PGT-A to screen whether an embryo has a normal chromosome count (46 chromosomes).
How NGS Works in PGT-A
- Embryo culture to the Blastocyst stage (day 5-6)
- Biopsy of a small sample from the part that will become the placenta (Trophectoderm)
- Genetic extraction from the sampled cells
- Sequencing with NGS — analyzing all 23 chromosome pairs
- Reporting — identifying whether each embryo is chromosomally normal or abnormal
At GFC, PGT-A using NGS has 99% accuracy with results within 24 hours.
How NGS Compares to Older Technologies
Before NGS, several embryo chromosome testing technologies existed, such as FISH and aCGH. NGS offers clear advantages:
| Older Technology | NGS | |
|---|---|---|
| Accuracy | Moderate | Very high (99%) |
| All 24 chromosome types | Not always complete | ✅ Complete |
| Detecting small abnormalities | Limited | ✅ More detailed |
| Speed of results | Slower | ✅ Fast (24 hrs at GFC) |
Why NGS Matters for ICSI Success
NGS accuracy allows doctors to confidently select chromosomally normal embryos, resulting in:
- Higher implantation success rates
- Reduced miscarriage risk from chromosomal abnormalities
- Fewer unnecessary transfer cycles
At GFC, combining ICSI with PGT-A using NGS raises the success rate from 60-65% to 70-75%.
What NGS Can Detect
NGS in PGT-A focuses on chromosome number (Aneuploidy), such as:
- Whether an embryo has extra or missing chromosomes
- Down syndrome risk (extra chromosome 21)
- Sex chromosome abnormalities
For testing specific genetic diseases (PGT-M), that’s a different type of test — consult your doctor directly.
FAQ
Are NGS and PGT-A the same thing?
No. PGT-A is the name of the embryo chromosome screening test, while NGS is the technology used to perform it. Simply put, NGS is the tool used to do PGT-A.
How accurate is NGS?
At GFC, NGS testing has 99% accuracy.
How long do NGS results take?
At GFC, results are available within 24 hours.
Does NGS testing require freezing embryos?
Yes. After biopsy for NGS, embryos are frozen and then transferred in an FET cycle once results are known.
Can NGS determine embryo sex?
Technically NGS can identify sex chromosomes, but selecting embryo sex for non-medical reasons is not permitted under Thai law.
How much does NGS/PGT-A cost at GFC?
PGT-A with NGS costs 37,900 THB at GFC.
Where can I consult about PGT-A?
Line @gfcclinic or call 097-484-5335
Summary
NGS (Next Generation Sequencing) is a modern genetic sequencing technology used in PGT-A to screen embryo chromosomes with 99% accuracy. It helps select chromosomally normal embryos, increasing success rates and reducing miscarriage risk.
At GFC, PGT-A with NGS costs 37,900 THB with results in 24 hours.
→ Learn more about PGT-A → PGT-A Explained → See ICSI services → ICSI at GFC → Book a Free Consultation or Line @gfcclinic | Tel: 097-484-5335
