Pre-implantation genetic diagnosis (PGD), conducted in conjunction with an IVF cycle, is a method to evaluate the genetic makeup of a patient’s embryos prior to selecting those to transfer into the patient’s uterus. PGD is performed for patients who are usually not infertile, but have risk for transmitting genetic diseases. More than 200 genetic disorders are currently amenable to this procedure.

PGD is performed in association with in vitro fertilization treatment where multiple eggs are obtained, fertilized and resultant embryos are cultured. PGD begins with the removal of 1-2 cells from selected embryos on the third day of culture when each embryo should contain between six and ten cells.

The procedure is called embryo biopsy and the extracted cell is subjected to genetic tests. The embryos (now each lacking one cell) are returned to culture and embryonic development continues. On the fifth day, the results of the genetic testing are used to select the most promising embryos for transfer at the blastocyst stage of development.