Preimplantation genetic testing (PGT) is when the genetic material (chromosomes) of an embryo is analyzed before the embryo being transferred to the uterus. There are different types of genetic testing that can be done. PGT for monogenic disorders, known as PGT-M, is used to look for a specific disease when one or both of partners are known to be carriers of an inherited genetic disorder.
PGT for aneuploidy (PGT-A), formerly referred to as PGS, is considered for women who have experienced recurrent pregnancy losses, for women of advanced age, for identifying genetic normality prior to embryo transfer or to determine an embryo’s sex (male or female). The term aneuploidy refers to having an abnormal amount of genetic material and is the leading cause of miscarriage and unsuccessful embryo implantation in the uterus. The goal of PGT-A is to identify chromosomally normal embryos which can then be selected for transfer, significantly increasing the chance of pregnancy.
For PGT cases, eggs are fertilized via intracytoplasmic sperm injection (ICSI) to create embryos. After 5-6 days of growth, cells from the outer portion of embryo are sampled and the embryo is then cryopreserved. The risk of damaging an embryo from the biopsy is approximately 1%. The embryo(s) remain at our clinic and the samples are sent to a reference lab for analysis. Results are obtained in approximately one week. Once results are available, a plan is made for the next step, which is usually a frozen embryo transfer (FET) in the next menstrual cycle. PGT may increase the likelihood of having a healthy baby.