Understanding PGT: A Guide to Genetic Testing Before IVF

Everything You Need to Know About Preimplantation Genetic Testing (PGT)

When planning IVF treatment, you may hear your fertility specialist mention Preimplantation Genetic Testing (PGT). For some patients, PGT can provide valuable information about embryos before they are transferred, helping fertility specialists make informed decisions as part of a personalised treatment plan.

Although PGT is not recommended for everyone, it may be beneficial in certain clinical situations, particularly where there is a known genetic condition, a history of recurrent miscarriage or repeated unsuccessful IVF cycles.

This guide explains what PGT is, how it works, who may benefit from it and answers some of the most common questions patients ask before starting treatment.

Quick Answer

Preimplantation Genetic Testing (PGT) is a laboratory technique used during IVF to analyse embryos for specific genetic or chromosomal abnormalities before embryo transfer. PGT does not improve the quality of an embryo or guarantee pregnancy, but in selected cases it may help identify embryos suitable for transfer based on the clinical indications for testing.

What Is PGT?

Preimplantation Genetic Testing (PGT) is performed during an IVF cycle after embryos have developed in the laboratory.

A small number of cells are carefully removed from an embryo by experienced embryologists and analysed in a specialist genetics laboratory. The embryo itself is typically frozen while the analysis is completed. Once the results are available, your fertility specialist will discuss the findings and advise whether one or more embryos are appropriate for transfer.

PGT is designed to provide additional genetic information; it is not a treatment for infertility in itself.

Why Is PGT Used?

The main aim of PGT is to identify embryos that meet the specific genetic testing criteria requested for that patient.

Depending on your clinical situation, PGT may be considered to:

• Reduce the chance of passing on certain inherited genetic conditions.
• Identify embryos with particular chromosomal findings where clinically indicated.
• Support treatment planning for patients with specific fertility histories.
• Provide additional information for couples at increased genetic risk.

Whether PGT is appropriate depends entirely on your individual medical circumstances.

Types of PGT

There are different forms of Preimplantation Genetic Testing, each with a different purpose.

PGT-A

PGT-A (Preimplantation Genetic Testing for Aneuploidy) assesses the number of chromosomes in an embryo. It may be considered in selected cases where chromosome abnormalities are more likely, although it is not routinely recommended for every patient.

PGT-M

PGT-M (Preimplantation Genetic Testing for Monogenic Disorders) is used when there is a known risk of passing on a specific inherited genetic condition, such as certain single-gene disorders.

PGT-SR

PGT-SR (Preimplantation Genetic Testing for Structural Rearrangements) may be recommended when one partner carries a balanced chromosomal rearrangement, such as a translocation, which can affect embryo development.

Who May Benefit from PGT?

PGT may be considered for patients who:

• Have a family history of certain inherited genetic conditions.
• Are known carriers of a genetic disorder.
• Have experienced recurrent miscarriage.
• Have had repeated unsuccessful IVF cycles in selected circumstances.
• Have a chromosomal rearrangement identified through genetic testing.
• Require additional genetic assessment as advised by their fertility specialist.

Not every IVF patient requires PGT. Your fertility specialist will recommend it only if it is clinically appropriate.

How Does the PGT Process Work?

The process usually involves several stages.

Step 1 – IVF Treatment

Eggs are collected and fertilised in the laboratory using IVF or ICSI, depending on your treatment plan.

Step 2 – Embryo Development

Embryos are carefully monitored for several days until they reach the appropriate stage for biopsy.

Step 3 – Embryo Biopsy

A highly trained embryologist removes a small sample of cells from the embryo. This procedure is performed using specialised laboratory equipment.

Step 4 – Genetic Analysis

The cell sample is sent to a specialist genetics laboratory where it is analysed according to the type of PGT requested.

Step 5 – Embryo Freezing

Embryos are usually cryopreserved while the genetic analysis is completed.

Step 6 – Consultation and Embryo Transfer

Once the results are available, your fertility specialist will discuss them with you and recommend the most appropriate next steps, including whether embryo transfer is suitable.

Does PGT Improve IVF Success?

This is one of the most frequently asked questions.

PGT does not improve the quality of an embryo or guarantee a successful pregnancy. Its purpose is to provide additional genetic information that may assist embryo selection in appropriate clinical situations.

Whether PGT is beneficial depends on factors such as your age, fertility history, genetic background and the reason it is being considered. Your fertility specialist will explain the potential advantages and limitations in your individual case.

What Are the Benefits of PGT?

Depending on the reason for testing, PGT may:

• Provide additional information about embryos before transfer.
• Help identify embryos affected by specific inherited conditions when testing is indicated.
• Support personalised treatment planning.
• Assist couples with known genetic risks in making informed decisions.

The potential benefits vary from patient to patient.

Are There Any Limitations?

Yes. It is important to understand that PGT has limitations.

For example:

• It cannot guarantee pregnancy or the birth of a healthy baby.
• Not all embryos will be suitable for testing.
• Results should always be interpreted alongside your overall clinical picture.
• Additional genetic counselling may be recommended in some situations.

Your fertility specialist will discuss these considerations with you before treatment.

Is PGT Safe?

Embryo biopsy is carried out by experienced embryologists using advanced laboratory techniques. As with any medical procedure, there are risks and limitations, and these should be discussed with your fertility team before deciding whether PGT is appropriate.

Common Myths About PGT

Myth: Everyone Having IVF Needs PGT

Fact: PGT is recommended only for selected patients where there is a clinical indication.

Myth: PGT Guarantees Pregnancy

Fact: No fertility treatment or genetic test can guarantee pregnancy or a live birth.

Myth: PGT Can Detect Every Genetic Condition

Fact: PGT is designed to detect the specific conditions or chromosomal abnormalities it has been requested to assess. It cannot identify every possible genetic condition.

Myth: PGT Replaces Prenatal Testing

Fact: PGT and prenatal testing have different purposes. Your healthcare team may still recommend prenatal screening or diagnostic testing during pregnancy where appropriate.

Questions to Ask Your Fertility Specialist About PGT

Before deciding whether PGT is right for you, consider asking:

• Is PGT recommended for my situation?
• Which type of PGT would be appropriate?
• What are the potential benefits and limitations?
• How will PGT affect my treatment timeline?
• Will my embryos need to be frozen?
• Should I speak with a genetic counsellor?
• What additional tests might be recommended?

These discussions can help you make an informed decision about your care.

Key Takeaways

• PGT is a specialised laboratory technique used during IVF to assess embryos for specific genetic or chromosomal conditions.
• It is not suitable or necessary for every patient.
• PGT does not guarantee pregnancy or improve embryo quality.
• The decision to use PGT should always be based on individual medical advice and, where appropriate, genetic counselling.
• A personalised consultation is the best way to determine whether PGT is appropriate for your fertility journey.

Frequently Asked Questions

Does every IVF patient need PGT?

No. PGT is recommended only when there is a medical or genetic reason for testing.

Can PGT identify all genetic conditions?

No. PGT is designed to test for specific genetic or chromosomal conditions and cannot detect every possible disorder.

Will PGT delay my IVF treatment?

PGT usually involves freezing embryos while genetic analysis is carried out, so embryo transfer often takes place in a later treatment cycle.

Is PGT painful?

No. The biopsy is performed on the embryo in the laboratory. Patients do not feel the procedure itself.

Can PGT improve my chances of having a healthy pregnancy?

PGT may provide additional information that supports treatment planning in selected cases, but it does not guarantee pregnancy or a healthy baby.

Speak to Our Fertility Specialists

Choosing whether to include Preimplantation Genetic Testing as part of your IVF treatment is an important decision. At Team Miracle Cyprus IVF Centre, our experienced fertility specialists take the time to understand your medical history, explain your options clearly and recommend a personalised treatment plan based on your individual needs.

If you would like to learn more about PGT or discuss whether it may be appropriate for your fertility journey, contact our team to arrange a consultation.

This article is provided for educational purposes only and should not replace professional medical advice. Treatment decisions should always be made following an individual consultation with a qualified fertility specialist and, where appropriate, a genetic counsellor.