PGT A Embryo Screening

PGT-A is a form of preimplantation genetic testing used during IVF to screen embryos for chromosome copy-number abnormalities. It helps the care team understand which embryos may be better candidates for transfer before an embryo is placed in the uterus.

PGT-A does not make an embryo healthier and does not guarantee pregnancy. Its value is in reducing blind embryo selection by combining morphology with genetic information.

What PGT-A results usually include

PGT-A reports often group embryos into three broad categories:

Euploid: the embryo has the expected chromosome number and is usually prioritized for transfer;
Mosaic: the biopsy sample may contain both normal and abnormal cell lines, requiring individualized clinical review;
Aneuploid: the embryo has an abnormal chromosome copy number and is usually not recommended for transfer.

Embryo grading and PGT-A results are different kinds of information. A high-grade embryo may still be aneuploid, and a euploid result still does not guarantee implantation.

Who may consider PGT-A

PGT-A may be discussed for:

Patients of advanced reproductive age;
Recurrent pregnancy loss where embryo chromosome error is suspected;
Repeated embryo transfer failure;
Patients with enough blastocysts to make screening useful;
Cases where previous embryo results suggest a need for additional selection data.

If only one or two embryos are available, the decision needs careful discussion. Testing may provide useful information, but it may also result in no embryo being available for transfer in that cycle.

What to ask the laboratory

Before choosing PGT-A, ask about:

Blastocyst culture to Day 5 or Day 6;
The experience of the biopsy team;
Freeze-thaw survival workflow;
How euploid, mosaic, and aneuploid results are reported;
How mosaic embryos are reviewed if they appear in the report.

The practical goal is not just to receive a report. It is to turn the report into a clearer transfer order and next-step plan.