Preimplantation genetic testing (PGT) examines embryos created using in vitro fertilization (IVF). PGT is used to diagnose genetically abnormal embryos or embryos that carry specific genes related to disease, before they are transferred into the patient's uterus. PGT helps avoid genetic defects at birth, miscarriage, and implantation failure and has since become an integral part of assisted reproductive technology.
Preimplantation genetic testing (PGT) is a genetic test performed on embryos created by in vitro fertilization (IVF). This testing screens embryos for abnormalities or genetic disorders, before implanting them in the uterus. The goal of PGT is typically to maximize the chances of creating a healthy pregnancy, or to avoid passing on genetic disease. It’s especially valuable when only one embryo is being implanted in the uterus.
Research indicates that embryo aneuploidy (extra or missing chromosomes) is the main cause of unsuccessful IVF cycles, as well as pregnancy loss. Abnormalities increase with rising maternal age, but can also be related to poor-quality sperm.
PGT is performed on a small sample of cells pulled from the embryo via needle biopsy. PGT may be done:
There are several types of PGT that may be used depending on the risk factors present. Tests include:
Chromosomal abnormalities in embryos can sometimes be caused by sperm. Studies show that genetically abnormal sperm, sperm DNA fragmentation (damaged sperm DNA), and Y chromosome microdeletions (genes missing from the Y chromosome, which is important for sperm production) can reduce embryo quality.
PGT may be performed if a patient: