PGT — embryo screening, when it actually matters.

What is PGT?

PGT (preimplantation genetic testing) is a group of laboratory tests performed on IVF embryos before transfer to the uterus. A small number of cells are biopsied from the embryo at the blastocyst stage (day 5 or 6 of culture), and analysed for specific genetic concerns. Embryos that test "normal" are transferred; embryos that test "abnormal" are not.

PGT replaces something the body would otherwise do silently — many genetically abnormal embryos fail to implant or are lost in early miscarriage. PGT lets us skip those failures by selecting embryos that are more likely to result in a healthy pregnancy. That sounds universally useful, but it isn't: in young women with good ovarian reserve, PGT adds cost without adding cumulative benefit.

The three types

PGT-A (aneuploidy screening)

Counts chromosomes. Detects whole-chromosome problems like Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), Patau syndrome (trisomy 13), and Turner syndrome (monosomy X). Most commonly used type.

PGT-M (monogenic disorders)

Tests for a single specific genetic disease known to run in the family. Used for thalassemia, cystic fibrosis, sickle cell disease, Huntington's, BRCA mutations, spinal muscular atrophy, and many others. Requires a tailored test design before the IVF cycle starts.

PGT-SR (structural rearrangements)

Used when a parent carries a balanced chromosomal translocation or inversion that puts embryos at risk of unbalanced rearrangements.

Who benefits from PGT?

• Women over 38 — embryo aneuploidy rates climb steeply with age. PGT-A is most cost-effective here.
• Recurrent pregnancy loss — particularly when prior losses showed chromosomal abnormalities.
• Recurrent implantation failure — multiple good-looking embryos that haven't implanted.
• Severe male factor — higher rates of aneuploidy in some severe cases.
• Known single-gene conditions — PGT-M to avoid passing on serious inherited diseases.
• Balanced translocations — PGT-SR to identify chromosomally balanced embryos.

How PGT works — step by step

1. Standard IVF cycle with stimulation and egg retrieval.
2. Extended embryo culture to day 5 or 6 (blastocyst stage).
3. Trophectoderm biopsy — the embryologist removes 5–10 cells from the outer layer of each viable blastocyst.
4. Embryo vitrification — embryos are flash-frozen while genetic analysis proceeds.
5. Laboratory analysis — takes 1–3 weeks depending on the lab and the type of testing.
6. Frozen embryo transfer — in a subsequent cycle, with the uterine lining prepared, a single tested-normal embryo is transferred.

Limitations and honest caveats

• Mosaicism — some embryos test as mixed (some cells normal, some abnormal). Interpretation is nuanced; some mosaic embryos result in healthy live births.
• False results are rare but possible — both false positives (a normal embryo discarded) and false negatives.
• Embryos lost to biopsy — rare but not zero.
• Doesn't replace prenatal diagnosis — confirmatory testing in pregnancy is still recommended.
• Doesn't improve egg quality — if all your embryos are abnormal, PGT will identify that fact but won't change it.

Cost in Hyderabad

PGT typically adds ₹50,000–₹1,00,000 to an IVF cycle in Hyderabad in 2026. Cost depends on the number of embryos tested, the type of PGT (A, M, or SR), and the genetics laboratory used. Costs include the biopsy procedure, embryo freezing during testing, and lab fees.

When NOT to do PGT

• First IVF cycle in a woman under 35 with good ovarian reserve and no relevant indication.
• When budget is constrained and the indication is borderline.
• When only one or two embryos are available — the math of selection doesn't favour PGT with so few embryos to choose from.

How I work

PGT is one of the most over-used technologies in fertility medicine right now. I use it selectively, with clear conversation about why it makes sense in your specific picture — or why it doesn't. The default in my practice is no PGT unless there's an evidence-based indication.