PGT: When and For Whom?

Embryo Genetic Testing (PGT) – When, For Whom? – A Comprehensive Guide

What is PGT?

Preimplantation genetic testing (PGT) involves taking a biopsy from embryos during IVF treatment for genetic analysis. The aim is to select a healthy embryo.

Types of PGT

• PGT-A: Chromosome number (aneuploidy)
• PGT-M: Single gene disorders
• PGT-SR: Structural chromosomal rearrangements

When Should It Be Performed?

PGT is performed in specific risk groups before embryo transfer during the IVF process.

1. Advanced Maternal Age

PGT-A may be recommended for patients over 35–38 years of age due to an increased risk of chromosomal anomalies.

2. Recurrent IVF Failure

It is used to genetically evaluate embryo quality after multiple failed transfers.

3. Recurrent Miscarriages

It is preferred to reduce miscarriages caused by genetic factors.

4. Genetic Disease Carrier Status

If there is a known genetic disease in the family, a healthy embryo can be selected with PGT-M.

5. Chromosomal Carrier Status

If one of the partners has a translocation or a structural chromosome problem, PGT-SR is performed.

For Whom Is It Not Necessary?

It may not be routinely necessary for young patients with good ovarian reserve and those undergoing their first IVF attempt.

How Is It Performed?

Typically, a trophectoderm biopsy is taken from a day 5 (blastocyst) embryo, and the embryos are frozen (freeze-all).

Advantages

• Selection of healthy embryos
• Reduced risk of miscarriage
• Increased success with single embryo transfer

Disadvantages

• Additional cost
• Interpretation challenges such as mosaicism
• Does not provide 100% guarantee

Clinical Reality

PGT is beneficial, especially in the right patient group, but it is not necessary for everyone.

Conclusion

The decision for PGT should be made based on individual risk factors. It is a powerful tool that increases success in the right patient.