Third generation IVF, also called preimplantation embryo genetic diagnosis technology, refers to the diagnostic method of biopsy and genetic analysis of embryos of patients with genetic risk during in vitro fertilization in order to select embryos without genetic diseases for implantation into the uterine cavity and thus obtain normal fetuses, which can effectively prevent the birth of children with genetic diseases. The indications are as follows: 1, monogenic genetic diseases: autosomal recessive genetic inheritance, meat B-beads production disorder anemia, fibrous cystic degeneration; autosomal dominant genetic diseases, such as a-beads production disorder anemia, X-chromosome companion genetic inheritance, such as hemophilia. 2.Triplet repeat sequence abnormalities: such as fragile X-chromosome syndrome. 3, chromosome number and structure abnormalities: aneuploidy, balanced translocation, Robertson translocation. 4, Repeated spontaneous abortions of unknown origin. 5, Patients with repeated failed in vitro implantation.