Preimplantation Genetic Testing
Preimplantation Genetic Testing/ Pre-Implantation Genetic Diagnosis
Preimplantation genetic testing (PGT-A) is a screening test that can be performed on embryos created via in vitro fertilization (IVF) to genetically analyse the embryos prior to transfer.
Why PGS is Recommended?
- One of the most common reasons that an embryo transfer does not result in a pregnancy is due to abnormal embryo genetics. PGT can ensure that the embryo selected for transfer has the correct number of chromosomes, thereby reducing the chances for a failed IVF cycle and reducing the chance of miscarriage
- Pre-implantation genetic diagnosis (PGD) /PGT-Sr or PGT-M is a laboratory procedure used in conjunction with in vitro fertilization (IVF) to reduce the risk of passing on inherited conditions. Some of the most common reasons for PGD are specific single-gene conditions (such as cystic fibrosis or sickle cell anemia) and structural changes of a parent’s chromosomes
- Typically, couples in need of these techniques are not infertile but have a family history of a condition and want to reduce the risk of having another child with significant health issues or early death. Through generally available genetic screening, however, occasionally couples who are seeking fertility treatment are found to be at risk of passing on an inherited condition, and PGD may be an option for them
- PGD is available for almost any inherited condition for which the exact mutation is known. A unique test must be developed for each couple, however. This test design may take up to several months to complete before beginning an IVF cycle.PGD uses IVF, in which multiple eggs are matured and retrieved. The oocytes are inseminated with sperm using intracytoplasmic sperm injection
- The resulting embryos are grown in culture until the Blasocyst stage, which is day five of embryo development. At this point, the embryo is biopsied with the removal of one to two cells. This process does not damage the cells remaining within the embryo
- The isolated cells are evaluated for specific genetic conditions. Embryos that are found to be unaffected are transferred back to the woman’s uterus on day five of embryo development