Introduction: Why Embryo Genetics Matter
One of the most significant advances in reproductive medicine over the last decade is our ability to screen IVF embryos for genetic abnormalities before they are transferred to the uterus. This technology — Preimplantation Genetic Testing, or PGT — has transformed IVF success rates and reduced the risk of miscarriage and genetic disease.
At PSFC OMR, Chennai, we offer PGT as part of personalised IVF protocols for couples who are likely to benefit from it.
What Is Preimplantation Genetic Testing (PGT)?
PGT is a laboratory technique used during IVF to analyse the genetic material of embryos before they are transferred into the uterus. A small number of cells (typically 5–10) are biopsied from the embryo at the blastocyst stage (day 5–6) and sent to a genetics laboratory for analysis.
The goal: identify chromosomally normal (euploid) embryos most likely to implant, develop, and result in a healthy live birth.
Types of PGT
| Type | What It Tests | Best For |
| PGT-A (Aneuploidy) | Checks all 23 chromosome pairs for extra or missing chromosomes | Advanced maternal age, recurrent miscarriage, repeated IVF failure |
| PGT-M (Monogenic) | Screens for specific single-gene disorders (e.g., cystic fibrosis, sickle cell) | Couples who are known carriers of genetic diseases |
| PGT-SR (Structural Rearrangements) | Detects chromosomal translocations or inversions | Couples where one partner has a chromosomal rearrangement |
How Does PGT Work? Step by Step
Step 1: IVF Cycle
The woman undergoes ovarian stimulation and egg retrieval as part of a standard IVF cycle. Eggs are fertilised with sperm in the laboratory.
Step 2: Embryo Development
Embryos are cultured in the laboratory for 5–6 days until they reach the blastocyst stage — the most advanced stage before transfer.
Step 3: Embryo Biopsy
A fertility specialist removes 5–10 cells from the outer layer (trophectoderm) of each blastocyst. This outer layer forms the placenta — not the baby — so it can be safely biopsied.
Step 4: Genetic Analysis
The biopsied cells are sent to a specialist genetics lab for analysis using Next Generation Sequencing (NGS) or other advanced techniques. Results are typically available within 7–14 days.
Step 5: Embryo Transfer
Only chromosomally normal (euploid) embryos are selected for transfer in a subsequent frozen embryo transfer (FET) cycle. Abnormal embryos are not transferred.
How PGT Improves IVF Success
| Benefit | How It Helps |
| Higher implantation rates | Only the most viable embryo is selected for transfer |
| Reduced miscarriage risk | Aneuploid embryos are the leading cause of early pregnancy loss |
| Single embryo transfer | Reduces twin/triplet pregnancies while maintaining success rates |
| Fewer IVF cycles needed | Better embryo selection means fewer failed transfers |
| Genetic disease prevention | PGT-M prevents passing serious hereditary conditions |
Who Should Consider PGT?
- Women over 35 (higher risk of chromosomally abnormal eggs)
- Couples with recurrent pregnancy loss (2+ miscarriages)
- Couples with repeated IVF implantation failure
- Known carriers of genetic disorders (PGT-M)
- Partners with chromosomal rearrangements (PGT-SR)
- Couples with a previous pregnancy affected by a chromosome condition
Limitations of PGT
PGT is highly accurate but not infallible. It carries a small risk of:
- Inconclusive results (requiring re-analysis or embryo discard)
- Mosaic embryos — embryos with a mix of normal and abnormal cells
- It does not screen for all genetic conditions — only those specifically tested
Your specialist at PSFC OMR, Chennai will discuss whether PGT is the right choice based on your specific clinical situation.
PGT at PSFC OMR, Chennai
We partner with accredited genetics laboratories to provide accurate, timely PGT analysis. Our embryologists and fertility specialists guide couples through every step of the testing process with transparency and compassion.
Conclusion
Preimplantation Genetic Testing represents one of the most powerful tools in modern fertility care. By selecting the healthiest embryos for transfer, PGT can significantly improve IVF outcomes and reduce the heartbreak of failed cycles and miscarriages.
Every embryo holds potential — PGT helps you identify the ones ready to grow into the family you dream of.
FAQs
Is PGT mandatory for IVF?
No. PGT is optional and recommended in specific clinical situations. Your fertility specialist will advise whether you are likely to benefit.
