Preimplantation genetic testing has transformed IVF outcomes for specific patient populations, enabling the selection of chromosomally normal embryos before transfer and dramatically improving success rates for eligible patients. Understanding who benefits most from PGT helps patients and their physicians make well-informed embryo selection decisions.
Types of Preimplantation Genetic Testing
PGT-A (for Aneuploidy) screens embryos for the correct number of chromosomes. Chromosomal abnormalities in embryos are a leading cause of implantation failure and early pregnancy loss, and the frequency of abnormal embryos increases substantially with maternal age. PGT-A identifies embryos with normal chromosomes (euploid) allowing physicians to prioritize them for transfer.
PGT-M (for Monogenic Disorders) tests embryos for specific inherited genetic conditions when one or both parents carry a known genetic mutation — including BRCA mutations, cystic fibrosis, sickle cell disease, and Huntington’s disease. This testing allows families with serious heritable conditions to build families without passing those conditions to their children.
The PGT Process in IVF
PGT requires embryo biopsy — performed on day 5 or 6 blastocyst-stage embryos where embryologists remove a few cells from the outer layer while leaving the inner cell mass intact. The biopsied cells are sent to a specialized genetics laboratory while embryos are cryopreserved awaiting results. Genetic analysis typically requires 1–2 weeks.
Who Benefits Most From PGT-A
Clinical evidence for PGT-A benefit is strongest for patients with advanced maternal age (typically 35+), patients with recurrent pregnancy loss, and patients with repeated implantation failure. In these populations, PGT-A improves both per-transfer success rates and reduces the risk of pregnancy loss.
The Fertility Institute of San Diego offers comprehensive genetic counseling and PGT services as part of their advanced IVF programs, helping patients understand their options and make informed decisions about embryo testing and selection.
Explore genetic testing and PGT options at the Fertility Institute of San Diego to learn how preimplantation genetic testing may improve your IVF outcomes and reduce the risk of pregnancy loss.
