What Are the Differences Between PGT-A, PGT-M and PGT-SR?

PGT, or preimplantation genetic testing, is an umbrella term for genetic testing performed in relation to embryos or oocytes during an IVF process. It is often associated with advanced IVF, but it should not be understood as one single test. PGT-A, PGT-M and PGT-SR address different genetic questions.

PGT-A refers to testing for aneuploidy, meaning abnormal chromosome number. It is used to assess whether embryos may have missing or extra chromosomes. It may be discussed in contexts such as advanced reproductive age, recurrent pregnancy loss, repeated implantation failure or embryo selection, but it is not automatically necessary for every IVF patient and cannot guarantee success.

PGT-M refers to testing for monogenic conditions. It is relevant when a family has a known risk of a specific inherited disorder caused by a pathogenic variant. PGT-M usually requires genetic counseling, confirmation of the familial variant and a customized testing strategy. It is not a broad screening test for all diseases.

PGT-SR refers to testing for chromosomal structural rearrangements. It may be relevant when one partner carries a balanced translocation, inversion or other structural rearrangement. Such carriers may be healthy but may produce embryos with unbalanced chromosomal material.

PGT usually involves embryo biopsy, laboratory testing and report interpretation. The process requires coordination among the IVF laboratory, genetics laboratory, physicians and genetic counselors. Results should be interpreted carefully, especially because embryo biology can be complex.

PGT can provide useful information for selected patients, but it cannot eliminate all genetic risk or guarantee pregnancy or a healthy child. Prenatal screening or diagnosis may still be recommended. This article is for educational purposes only and does not constitute medical advice.