The answer is: no. PGT-A (preimplantation genetic testing for aneuploidy) can substantially reduce the risks of implantation failure and miscarriage caused by chromosomal abnormalities, but due to the limitations of the technology principle, it cannot 100% completely rule out embryo chromosomal abnormalities.
The core reason for the limited accuracy
PGT-A only samples the trophectoderm cells on the embryo outer layer (which develop into the placenta) for testing, whereas the inner cell mass that will develop into the fetus may have a chromosomal composition different from the trophectoderm - the phenomenon known as embryo mosaicism - which is the root of why the test cannot be absolutely accurate.
What are false positives and false negatives, respectively?
- False positive: The embryo chromosomes are actually normal, yet the test result judges it as abnormal. This is mostly caused by sampling bias or cellular mosaicism and may lead to a transplantable embryo being wrongly discarded.
- False negative: The embryo actually has chromosomal abnormalities, yet the test result shows normal. This is common with low-level mosaicism and small chromosomal segment abnormalities that exceed the resolution of the testing technology, resulting in missed detection.
Final reminder
PGT-A is a screening tool, not the gold standard for clinical diagnosis. Even after transferring an embryo with a normal PGT-A result, standardized prenatal examinations must still be completed as instructed by the physician after conception, to further confirm the fetal chromosomal status.
This article is for science popularization and information sharing only, and does not constitute medical advice. Assisted reproduction plans must be formulated by the attending physician based on the individual's physical condition; individual outcomes vary and are subject to formal evaluation at a licensed medical institution.
