Preimplantation Genetic Testing

At Columbia University Fertility Center, genetics experts from across Columbia University work together to ensure the best possible outcomes through detection of chromosomal abnormalities and genetic defects in embryos.

Preimplantation genetic testing (PGT) may be recommended during in vitro fertilization (IVF) to test the embryos for certain genetic diseases or chromosomal abnormalities. Once an egg is fertilized and grows into an optimal number of cells, a biopsy of the embryo is performed and cells are removed to be analyzed for potential genetic conditions.

This process allows the selection of the healthiest embryos for transfer. Selection is also possible based on gender balancing. PGT typically requires that the embryos be frozen in order to be transferred at a later time in a frozen embryo transfer.

What conditions do these procedures test for?

PGT for monogenic disease (PGT-M) is used to test for single gene diseases that are inherited from one or both of the parents. Some of these disorders include Sickle Cell Anemia, Tay Sachs, Cystic Fibrosis, Huntington’s Disease, and others. A couple may know of this risk from a prior affected child, family history, or having a genetic carrier screening panel performed prior to attempting pregnancy. These panels are offered to all patients at Columbia University Fertility Center.

PGT for aneuploidy (PGT-A) evaluates the number of chromosomes in an embryo. Normal embryos, and babies, have two copies of each chromosome numbered one through 22 and XX for a girl or XY for a boy. Numerical chromosome abnormalities may cause an embryo to fail to implant, miscarry, or cause a condition such as Down syndrome.

Who should have these procedures performed?

These procedures may be appropriate for patients who are known carriers of genetic diseases, have a history of multiple miscarriages (recurrent pregnancy loss), or have repeated IVF failures with no identifiable causes. PGT-A is available to any one undergoing IVF and may help with selection when single embryo transfer is being performed. Single embryo transfer is strongly recommended after PGT-A. PGT provides valuable knowledge and diagnosis to our doctors and genetic counselors to ensure the proper treatment and care for the patient. We will work with you before and after PGT to help you make the most informed decision possible.