Embryo testing, also known as Preimplantation Genetic Testing (PGT), is a sophisticated procedure performed during the IVF process to examine the genetic and chromosomal makeup of developing embryos before they are selected for transfer to the uterus. This process typically involves safely biopsying a small number of cells from the outer layer of the embryo, usually when it reaches the blastocyst stage around day five or six of development. While the genetic analysis is being conducted by specialized laboratories, the embryos are safely cryopreserved.
This advanced screening is crucial because an embryo can look healthy under a microscope but still carry genetic abnormalities. The testing can identify differences such as aneuploidy (an abnormal number of chromosomes, like missing or extra chromosomes), which is the most common cause of implantation failure and early miscarriage. Additionally, for partners aware of carrier status, it can screen for specific inherited single-gene disorders to prevent passing on certain conditions.
By providing a deeper understanding of embryo viability, this testing allows fertility teams to select embryos with the healthiest genetic profiles for future transfer. Ultimately, embryo testing can significantly reduce the risk of miscarriage, improve overall pregnancy outcomes, support healthier single-embryo transfer practices, and provide patients with much greater confidence and peace of mind in their family-building journey.