PGT-A Testing, Explained

Preimplantation Genetic Testing for Aneuploidy (PGT-A) is one of the most commonly discussed — and sometimes overstated — technologies in modern IVF. Here's what it actually does.

What PGT-A tests for

PGT-A screens embryos for the correct number of chromosomes before transfer. Embryos with an abnormal chromosome count (aneuploidy) are significantly less likely to result in a successful pregnancy, and more likely to end in early miscarriage if implantation does occur. PGT-A identifies which embryos have a normal chromosome count, which can inform which embryo is prioritized for transfer.

How the process works

1. A small, safe biopsy of a few cells is taken from the embryo at the blastocyst stage (day 5–6), which does not harm the embryo's ongoing development
2. The biopsied cells are sent to a genetics lab for chromosomal analysis
3. Results typically take 1–2 weeks, which is why PGT-A cycles usually involve freezing embryos and transferring later, rather than a fresh same-cycle transfer

Who benefits most

PGT-A is most clearly indicated for patients with a history of recurrent miscarriage, advanced maternal age, or prior failed IVF cycles with normal-appearing embryos — situations where chromosomal abnormality is a more likely contributing factor. It's a genuine clinical tool for these situations, not a universal requirement for every IVF patient.

What it costs and what it adds to your timeline

PGT-A adds a real cost on top of a standard IVF cycle, and because it requires freezing embryos while results are pending, it typically shifts the process to a frozen transfer on a second visit rather than a single-trip fresh cycle. See our protocol timing guide for how this affects trip planning.