The first generation of IVF is called in vitro fertilization embryo transfer, in which the eggs are removed from the woman’s body, the man retrieves the sperm through masturbation, and after the semen is processed, the sperm with good vitality is placed around the eggs and incubated in an incubator to allow the sperm to fertilize the eggs on its own and develop into embryos, which are then transferred to the woman’s body. The first generation of IVF mainly solves the problem of obstruction of the fallopian tubes or lack of sperm-egg contact in the female partner, as well as ovulation disorders, endometriosis, moderate oligospermia in the male partner, and unexplained infertility. After 3-6 cycles of IUI treatment and still no pregnancy, first generation IVF is used. 2. Second generation IVF is intracytoplasmic single sperm injection, where high quality sperm are selected under a microscope and injected directly into the oocyte plasma. If the sperm is too little or the sperm deformity rate is too high and the acrosome enzyme defect cannot penetrate the egg, natural fertilization cannot be achieved and only the second generation can be used; 3. Third generation IVF, also known as preimplantation genetic diagnosis, or genetic screening, has made great progress in recent years with the development of genetic testing technology, which can take one or a few cells at the early stage of embryo development to check the embryo chromosome The whole ploidy or genes can be checked and normal genetic embryos can be screened for transfer.