PGT Testing Explained: PGT-A, PGT-M & PGT-SR for a Healthy Baby

If you have faced a failed IVF cycle, recurrent miscarriage, or carry a known genetic condition in your family, you may have already heard your fertility team mention PGT testing. Preimplantation genetic testing lets embryologists examine an embryo’s genetic makeup before transfer, helping your care team choose the embryo with the best chance of a healthy pregnancy. At GynoLife IVF in Nicosia, Cyprus, we use PGT as one tool among several to help patients make more informed decisions — not as a guarantee, but as a way to reduce certain risks.

What Is PGT Testing?

PGT stands for Preimplantation Genetic Testing. It is performed after eggs are fertilised in the laboratory and embryos have grown to the blastocyst stage, usually around day five or six. A small number of cells are gently removed from the embryo’s outer layer (which forms the placenta, not the fetus) in a step called trophectoderm biopsy, then sent to a specialised genetics laboratory for analysis while the embryo is safely frozen.

The core idea behind any pgt test IVF pathway is simple: instead of transferring an embryo and hoping it is chromosomally or genetically normal, the lab checks first. This does not change the embryo’s biology — it only gives more information to guide which embryo, if any, is transferred.

The Three Types of PGT Testing

“PGT” is an umbrella term. Depending on the medical history of the couple, one of three distinct tests may be recommended.

PGT-A (Aneuploidy Screening)

PGT-A screens embryos for an abnormal number of chromosomes, known as aneuploidy. Most first-trimester miscarriages are caused by chromosomal errors, and the likelihood rises with maternal age. PGT-A is the most commonly used form of PGT testing and is often considered for recurrent miscarriage, repeated implantation failure, or advanced maternal age. Selecting a chromosomally normal (euploid) embryo does not guarantee a live birth, but published data suggests it can lower miscarriage risk linked to chromosomal causes and may reduce the number of transfers needed in certain patient groups.

PGT-M (Monogenic/Single-Gene Disorders)

PGT-M is used when one or both intended parents are known carriers of a specific inherited condition caused by a single gene mutation — for example cystic fibrosis, beta-thalassaemia, or spinal muscular atrophy (SMA). Because PGT-M targets a known familial mutation, it requires genetic counselling and a bespoke test designed around the family’s mutation before the cycle begins. It is recommended for couples with a family history of a genetic disease, known carrier status, or a previously affected child or pregnancy.

PGT-SR (Structural Rearrangements)

PGT-SR is offered when one partner carries a chromosomal structural rearrangement, such as a balanced translocation or inversion. These rearrangements often do not affect the carrier’s own health but can lead to embryos with unbalanced chromosome structures, strongly associated with recurrent pregnancy loss or failed implantation. PGT-SR helps identify embryos with a balanced chromosomal structure for potential transfer.

How the Biopsy and NGS Process Works

The pgt testing process follows several careful steps within the broader IVF cycle:

• Fertilisation and culture: Eggs are fertilised via ICSI and cultured until they reach the blastocyst stage.
• Trophectoderm biopsy: A few cells are carefully removed from the outer layer of a well-developed blastocyst.
• Vitrification: The biopsied embryo is immediately flash-frozen so it can be safely stored while results are pending.
• Whole genome amplification and NGS: The cells undergo Next Generation Sequencing (NGS), the current gold-standard technology for detecting chromosomal and genetic abnormalities.
• Result review: A geneticist and your specialist review the report and discuss which embryo(s), if any, are suitable for a future frozen embryo transfer (FET).

Because biopsy and freezing are involved, PGT cycles typically move to a frozen embryo transfer rather than a fresh one, giving the lab time to complete the analysis.

Who Benefits From PGT?

PGT testing is not automatically recommended for every IVF patient. Your GynoLife specialist will discuss whether it is appropriate based on your history, which may include recurrent pregnancy loss, multiple failed IVF or embryo transfer attempts, advanced maternal age, known carrier status for an inherited condition, a known chromosomal translocation in either partner, or a previous pregnancy or child affected by a genetic condition.

An Important Legal and Ethical Note

PGT testing exists to identify medically significant chromosomal and genetic conditions — it is a medical tool, not a family-planning preference tool. Using PGT to select an embryo’s sex for non-medical, social reasons is not legal in Cyprus and is not something GynoLife IVF offers or supports. Where sex-linked information is unavoidably generated as part of a medical PGT-M result, it is handled strictly within the applicable legal framework and solely for medical purposes.

Limitations and Mosaicism

PGT is a powerful screening tool, but it is not infallible, and patients deserve an honest picture of its limits:

• It reduces risk, it does not eliminate it. A “normal” result improves the odds of a healthy pregnancy but does not guarantee one; implantation can still fail for reasons unrelated to the embryo’s genetics.
• Mosaicism. Some embryos contain a mix of normal and abnormal cells. Because only a small biopsy sample is tested, results are not always fully representative of the entire embryo, and mosaic results require individualised counselling.
• Biopsy carries a small procedural risk, and not every embryo survives biopsy and vitrification, though this is uncommon with experienced laboratories.
• PGT does not test for everything. It targets the specific issues relevant to the test ordered — it is not a comprehensive health guarantee for the future child.

Frequently Asked Questions

Does PGT testing guarantee a healthy baby?

No. PGT reduces certain genetic and chromosomal risks by identifying embryos less likely to carry the abnormality tested for, but it cannot guarantee pregnancy, live birth, or a condition-free child, since not every health condition is genetic or detectable through PGT.

How long do PGT results take?

Turnaround depends on the referral laboratory, but results are typically available within one to two weeks, after which your specialist discusses findings and plans a frozen embryo transfer if a suitable embryo is available.

Can PGT be combined with other IVF treatments?

Yes. PGT-A, PGT-M, and PGT-SR are add-on steps within a standard IVF or ICSI cycle, alongside other treatment your GynoLife specialist recommends.

Discuss PGT Testing With GynoLife IVF

Every patient’s genetic history is different, which is why PGT is never a one-size-fits-all recommendation. Our team in Nicosia, Cyprus can review your medical background, explain whether PGT-A, PGT-M, or PGT-SR may be relevant to you, and walk you honestly through the realistic benefits and limitations before you decide. Contact GynoLife IVF to schedule a consultation and ask any questions about the PGT test IVF process.