Preimplantation genetic diagnosis (PGD) is considered for couples who are at high risk of passing on a serious genetic disorder to their offspring. PGD is a genetic test of the embryo that is carried out before it is implanted in the uterus. Usually around five days after fertilization, a few cells are removed from the embryo and genetically examined. This removal usually does not affect the embryo. Then, those embryos that are not affected by the genetic modification being studied are selected for transfer into the woman’s uterus.
Even if a couple does not have fertility problems, performing PGD still requires in-Vitro-Fertilisation(IVF/ICSI) so that the embryos can be examined in the laboratory.