Preimplantation Genetic Testing for Aneuploidy(PGT-A)
procedureDefinition
Genetic testing of embryos prior to transfer to screen for chromosomal abnormalities (incorrect number of chromosomes).
In IVF Treatment
PGT-A involves a trophectoderm biopsy of the blastocyst on Day 5-6. Embryos are then frozen while results are awaited. Clinics may prioritize embryos reported as euploid, meaning the biopsy sample showed an expected chromosome copy-number pattern. PGT-A can inform embryo selection in some situations, but it does not guarantee implantation, pregnancy, or live birth.
Frequently Asked Questions
Should everyone do PGT-A?
Not necessarily. PGT-A is most beneficial for patients over 38, those with recurrent pregnancy loss, or those who have had multiple failed transfers. For younger patients with good prognosis, it may not add benefit and does carry a small risk from the biopsy.
Can PGT-A miss chromosomal problems?
No test is 100% accurate. PGT-A has a small false-positive and false-negative rate. Normal-looking embryos can occasionally have abnormalities, and a small proportion of PGT-A "abnormal" embryos can self-correct.