PGD combines recent advances in genetics and reproductive medicine. The early embryo is examined after IVF for inherited diseases or to determine the sex for sex-related genetic disorders. The process starts with a basic IVF. When the embryo is at the 6- to 8-cell stage, one or two cells are removed and sent to the genetic laboratory for diagnosis. The unaffected embryos are then transferred into the mother’s uterus.
In certain situations in which the genetic problem is only with the female, a polar body can be removed from the eggs and tested before fertilization.
PGD is recommended when embryos may be affected by a certain genetic condition. Only healthy and normal embryos are transferred into the mother's uterus, preventing miscarriages, pregnancy termination or birth defects. Primary candidates for PGD include: