Preimplantation genetic diagnosis (PGD) enables people with an inheritable condition in their family to avoid passing it on to their children. It involves checking the genes and/or chromosomes of embryos created through IVF. The evaluation process takes at least 7 days. Only the selected healthy embryos are placed in the uterus of the mother. The remaining embryos are kept frozen for future use. PGD involves the testing of 100 different genetic conditions.