In brief: Testing embryos genetically before they are transferred to the uterus is called preimplantation genetic testing (PGT); this analysis usually relies on an advanced reading method called NGS. This article answers one question: who actually needs IVF genetic testing, and should everyone have it?

What is PGT, and what does NGS do?

PGT (preimplantation genetic testing) means taking a very small cell sample from embryos created during IVF and examining the embryo’s chromosomes or a specific gene region. NGS (next-generation sequencing) is the laboratory technology that reads that sample with high accuracy. In other words, PGT describes “what we look for” and NGS describes “how we read it.” You can see where genetic testing fits into every step of treatment on our page detailing IVF treatment in Istanbul.

What are the main types of PGT?

• PGT-A: Examines the number of chromosomes in an embryo, to identify embryos carrying a numerical chromosome abnormality (aneuploidy).
• PGT-M: When a single-gene disease is known in the family (for example thalassemia, cystic fibrosis, SMA), it helps identify embryos that do not carry that condition.
• PGT-SR: When one parent has a structural chromosome rearrangement (such as a translocation), it is used to select balanced embryos.

Who is IVF genetic testing recommended for?

Genetic testing is not a routine step for every couple; it provides meaningful benefit in specific situations. The groups it is most often recommended for include:

• Advanced maternal age: The chance of chromosome errors in embryos rises with age, so PGT-A is discussed more often in this group.
• Recurrent pregnancy loss: It may be considered to evaluate chromosomal causes in couples with repeated miscarriages.
• Repeated failed transfers: When pregnancy does not occur despite healthy-looking embryos, it can help with embryo selection.
• Known family genetic disease: If the couple carries a single-gene condition, PGT-M targets an unaffected embryo.
• Chromosome rearrangement: If one parent has a translocation, PGT-SR is appropriate.
• Severe male factor: In some severe sperm problems, it can add information during embryo assessment.

Most situations that call for genetic testing are closely tied to how age affects the process. To explore that link, our article on IVF success rates by age is a good starting point.

And who doesn’t need it?

For many younger couples with good ovarian reserve, no history of miscarriage, and a first attempt, genetic testing is not mandatory. The test has a cost, an extra procedural step (embryo biopsy) and a process that requires freezing the embryos. The decision is therefore based on your history and embryo picture, not a blanket “everyone should have it.”

How does the process work if testing is done?

When PGT is planned, embryos are usually biopsied on day 5–6 (blastocyst stage) and then frozen by vitrification. Once results arrive, a suitable embryo is transferred in a separate cycle. For this reason genetic testing is most often planned together with a frozen embryo transfer (FET). The process may take a few extra weeks, but the goal is the highest chance with the most suitable embryo.

Does genetic testing guarantee pregnancy?

No. PGT does not guarantee pregnancy or a healthy birth; it is a tool that helps with embryo selection. The test gives information about the chromosomes or gene region it examines; it does not provide a definitive answer for every possible condition. Intermediate results such as “mosaic embryos” can also occur, and interpreting them requires expertise. Genetic testing should therefore be assessed within your overall treatment plan, not on its own.

What is considered when deciding?

• Your age and number of embryos.
• Your history of miscarriage or failed transfers.
• Known genetic disease or carrier status in the family.
• Whether a chromosome rearrangement is present.
• Your priorities and how well the process suits you.

These points are weighed together; the aim is to avoid unnecessary procedures while offering the right test, at the right time, to couples who will benefit.

Frequently asked short questions

Does biopsy harm the embryo? In experienced hands, blastocyst biopsy is considered safe; the vast majority of embryos come through it well.

If I have PGT-A, am I guaranteed a healthy baby? No; the test helps reduce risk but does not provide a guarantee.

Is it needed in every IVF attempt? No; it is recommended when there is an indication, and may not be done routinely otherwise.

Appointment and contact

To clarify whether IVF genetic testing is right for you and to build the most suitable plan together, you can request an appointment at our clinic at Biruni University Hospital in Istanbul. Instead of applying the same approach to every couple, we map out a personalized plan aimed at the highest chance based on your own data.

This article is for information only and does not replace a personal examination and medical evaluation. Decisions about genetic testing and treatment should be made together with your physician after your results and history are assessed.