Medically reviewed by Dr. Shweta Agarwal, MBBS, DGO. Last updated: June 2026.
Information on this page is educational and does not replace a medical consultation. Outcomes depend on individual clinical factors.
Aansh Hospital & IVF Center is a fertility clinic serving Vidarbha and northern Telangana, with its headquarters and in-house embryology lab led by Senior Clinical Embryologist Aayush Agarwal, Ph.D. Treatment is led by Dr. Shweta Agarwal (MBBS, DGO). In Marathi, preimplantation genetic testing is referred to as भ्रूण अनुवांशिक चाचणी — genetic testing of the embryo before it is placed in the womb. You can verify our government ART registration on the National ART & Surrogacy Registry.
What is PGT, and when does chromosomal or genetic testing of an embryo help?
The majority of human embryos — even those that appear healthy under the microscope — carry chromosomal abnormalities. These arise naturally during egg and sperm formation and increase with age. An embryo with the wrong number of chromosomes (aneuploidy) usually either fails to implant or miscarries early; it very rarely results in a continuing pregnancy. PGT identifies embryos with the correct chromosomal or genetic profile before transfer, so that the embryo selected for transfer has already passed a genetic health check. This reduces — but does not eliminate — the risk that a given transfer fails because of chromosomal problems.
PGT is not a routine add-on for everyone going through IVF. It is most useful in specific situations: older maternal age, a history of recurrent pregnancy loss or recurrent implantation failure, or when one or both partners carry a known heritable condition. Dr. Shweta Agarwal discusses whether PGT is likely to be helpful in your individual situation during the fertility assessment consultation.
What are the three types of PGT, and which is right for you?
PGT is a category of tests, not a single test. The three types each address a different kind of genetic concern.
PGT-A — testing for the correct number of chromosomes (aneuploidy)
PGT-A screens embryos to confirm they have the normal chromosome count (46 chromosomes in 23 pairs). An embryo with an extra or missing chromosome is called aneuploid; a chromosomally normal embryo is called euploid. PGT-A identifies euploid embryos for transfer.
Who PGT-A is most commonly recommended for:
- Women aged 37–38 and older, where the aneuploidy rate in eggs rises significantly with age
- Couples with a history of two or more pregnancy losses (per ASRM 2020 / ESHRE 2023) — see recurrent pregnancy loss
- Couples with three or more failed IVF transfers with good-quality embryos — see recurrent implantation failure
- Couples where a previous pregnancy was diagnosed with a chromosomal condition
- Couples with severe male-factor infertility where sperm DNA fragmentation is a concern
PGT-A does not screen for all possible conditions — it tests for extra or missing whole chromosomes. It will not detect every type of genetic abnormality.
PGT-M — testing for a known single-gene (monogenic) inherited disorder
PGT-M is designed for couples who carry a known heritable single-gene condition and want to avoid passing it on. Before the IVF cycle begins, a specialist genetics laboratory designs a custom probe specific to the family's mutation. Embryos are then tested to identify those that are unaffected (do not carry two copies of the faulty gene, in the case of recessive conditions) or do not carry the mutation at all.
Conditions for which PGT-M is commonly used:
- Thalassaemia — particularly relevant in India, where carrier rates are significant in many communities; PGT-M allows thalassaemia carrier couples to have IVF and only transfer unaffected embryos
- Sickle cell disease
- Cystic fibrosis
- Spinal muscular atrophy (SMA)
- Huntington's disease
- BRCA1/BRCA2 (hereditary breast/ovarian cancer gene variants), on careful counselling
PGT-M requires thorough genetic counselling for both partners before IVF begins, a custom probe-design phase (which takes several weeks and adds to cost — see Costs & EMI for current pricing), and a clear understanding of what will be done if few or no unaffected embryos are found.
PGT-SR — testing for chromosomal structural rearrangements
PGT-SR is used when one or both partners carry a structural chromosomal rearrangement — most commonly a balanced translocation or inversion. People with a balanced rearrangement are usually themselves healthy, because all the necessary genetic material is present even if rearranged. However, the embryos they produce have a significantly elevated risk of carrying an unbalanced rearrangement — which typically causes miscarriage or a serious chromosomal condition. PGT-SR identifies embryos whose chromosomal arrangement is balanced or structurally normal, reducing the risk of a miscarriage from an unbalanced embryo.
Genetic counselling before PGT-SR is essential to map the precise rearrangement and design the test. If you and your partner have experienced repeated miscarriages and have not been tested for a balanced translocation, this is worth raising during your fertility assessment.
How is PGT performed, step by step?
PGT sits within a standard IVF cycle. The key difference is that after the embryos reach the blastocyst stage (guided by blastocyst culture), a biopsy step is added before any embryo is transferred. All PGT cycles use a freeze-all strategy: embryos are vitrified immediately after biopsy, results are awaited, and the selected embryo is transferred in a subsequent frozen embryo transfer cycle. There is no fresh transfer in a PGT cycle.
- Genetic counselling (before IVF begins): Both partners receive counselling so they fully understand what each test can and cannot determine, what different results mean, and what decisions may arise (for example, if all embryos are affected or if a mosaic result is returned). Both partners must provide written informed consent prior to embryo biopsy and genetic testing (per ART Act 2021). For PGT-M and PGT-SR, the probe or test is designed at this stage.
- IVF stimulation and egg retrieval: As per the standard IVF protocol — ovarian stimulation, monitoring, trigger injection, egg retrieval under sedation.
- Fertilisation with ICSI: All PGT cycles use ICSI for fertilisation to ensure paternity certainty and to prevent residual sperm from contaminating the biopsy sample.
- Blastocyst culture (Day 5–6): Embryos are grown to the blastocyst stage in the in-house embryology lab. Only blastocysts — not Day 3 embryos — are biopsied. See blastocyst culture for how this works.
- Trophectoderm biopsy: The embryologist carefully removes 3–5 cells from the trophectoderm — the outer layer of the blastocyst, which forms the placenta — leaving the inner cell mass (which forms the baby) completely undisturbed. This is the standard technique in modern PGT programmes.
- Vitrification (freeze-all): Each biopsied blastocyst is immediately vitrified (fast-frozen) while its cells are analysed.
- Genetic analysis (external accredited laboratory): Biopsied cells are sent to a specialist genetics laboratory for analysis. Analysis typically takes 7–14 days.
- Results review: Dr. Shweta Agarwal and the embryologist review the results together. Euploid or unaffected embryos are identified for transfer; results with mosaicism are discussed in counselling before a decision is made.
- Frozen embryo transfer: The selected embryo is warmed and transferred in a subsequent prepared cycle. See frozen embryo transfer for what this involves.
Who is most likely to benefit from PGT?
The following groups are most commonly offered PGT at a consultation, though the final decision is always individualised:
- Women aged 37 or older embarking on IVF, where age-related aneuploidy makes chromosomal screening of embryos more informative
- Couples with recurrent pregnancy loss (two or more pregnancy losses, per ASRM 2020 / ESHRE 2023) — PGT-A can determine whether chromosomal abnormality in embryos has been a contributing factor; see recurrent pregnancy loss
- Couples with recurrent implantation failure (typically three or more failed transfers with good-quality embryos) — see recurrent implantation failure
- Carrier couples — where one or both partners are known carriers of a single-gene disorder (thalassaemia, sickle cell, cystic fibrosis, SMA, and others), PGT-M allows transfer of only unaffected embryos
- Couples with a known balanced translocation or structural chromosomal rearrangement, where PGT-SR substantially reduces the risk of an unbalanced embryo being transferred
- Couples with a previous pregnancy affected by a chromosomal condition, where aneuploidy screening in the next cycle is appropriate
PGT is not routinely indicated for all couples undergoing IVF, particularly younger women with good ovarian reserve and no prior pregnancy loss. The evidence for PGT-A in low-risk groups is less clear, and Dr. Shweta Agarwal will discuss the likely benefit honestly in your specific situation.
What can PGT tell you — and what are its limitations?
PGT is a powerful genetic tool, but it is important to understand what it can and cannot do.
What PGT can do:
- Identify embryos that appear chromosomally normal (euploid) for the chromosomes tested — PGT-A
- Identify embryos that do not carry a specific tested single-gene disorder — PGT-M
- Identify embryos with a balanced or normal chromosomal arrangement when a parent carries a structural rearrangement — PGT-SR
- Reduce the risk that a given transfer fails because of a chromosomal or specific genetic cause
What PGT cannot do:
- Guarantee a pregnancy. A chromosomally normal embryo still needs to implant and develop. Implantation depends on uterine factors, embryo quality beyond chromosomal content, and factors that no test can fully assess. No IVF step can guarantee a pregnancy.
- Screen for every possible condition. PGT-A tests for extra or missing whole chromosomes; it does not detect single-gene disorders, small structural changes, or every possible genetic variant. PGT-M tests only for the specific condition it was designed for.
- Eliminate mosaicism entirely. The biopsy samples the trophectoderm (outer layer), not every cell of the embryo. A small number of embryos will show a mosaic result — meaning some cells appear normal and some do not. Mosaic embryos require specialist counselling to decide whether transfer is appropriate. Mosaicism is a real nuance of the technique, not an error.
- Replace genetic counselling. The results of PGT — particularly PGT-M and PGT-SR — require careful interpretation with clinical context. A result is not a simple pass/fail for all purposes.
What does PGT add to cost, and what does the process mean practically?
Adding PGT to an IVF cycle changes the practical shape of treatment: there is no fresh transfer, and the process is longer — typically 6–10 weeks from the start of stimulation to embryo transfer, compared with 4–6 weeks for a standard IVF cycle without PGT.
Cost is higher than IVF alone because PGT adds the biopsy step, the external laboratory genetic analysis, and the frozen embryo transfer cycle. PGT-M also involves an upfront probe design fee before the IVF cycle begins. You receive a transparent written cost estimate before anything begins, and the final cost is confirmed after your consultation and clinical assessment.
Final cost depends on individual clinical evaluation — see Costs & EMI for current pricing.
- 0% EMI options are available (3–24 months).
- See IVF cost & 0% EMI for a full breakdown.
Not all embryos in a PGT cycle will be suitable for biopsy (only blastocysts can be biopsied). Some cycles produce no euploid or unaffected embryos — this reflects the underlying embryo biology and is a result of the test, not a failure of the process itself. Your embryologist and doctor will discuss what this means for next steps.
Can PGT be used to choose the sex of the baby?
No. This is never done at Aansh Hospital & IVF Center, and it is a criminal offence under Indian law.
Sex selection — choosing which embryo to transfer based on its sex — is strictly prohibited under the Pre-Conception and Pre-Natal Diagnostic Techniques (PCPNDT) Act, 1994. The law applies to all techniques, including PGT. Violation carries criminal penalties including imprisonment.
PGT at Aansh is performed solely to assess the chromosomal and genetic health of embryos — for aneuploidy (PGT-A), a known heritable single-gene disorder (PGT-M), or a structural chromosomal rearrangement (PGT-SR). Sex is not communicated to patients as a basis for embryo selection. Any request for sex-based embryo selection is declined.
This is not a matter of policy preference — it is the law.