IVF is actually the common name for in vitro fertilization embryo transfer technology, which is a type of assisted reproductive technology. It involves taking out the wife’s eggs and the husband’s sperm, forming a fertilized egg outside the body, and culturing it into an early embryo before transferring it to the wife’s uterus to grow and develop normally within the mother’s body. IVF was originally designed for women with blocked fallopian tubes causing infertility. These women were unable to conceive naturally because their fallopian tubes were blocked and it was difficult for sperm and eggs to combine, so a test tube was used to replace their fallopian tubes, hence the image metaphor of IVF. With the development of medicine, later on, stubborn ovulation disorder, endometriosis, immune, cervical or unknown factors causing infertility were gradually included as indications for IVF. All of the above are female factors causing infertility. If the male partner has normal sperm, the most traditional conventional fertilization method is used to culture the removed sperm and eggs together and let them combine naturally to form a fertilized egg, then culture it for 3-5 days to form an embryo and then transfer it to the wife’s uterus, which is often referred to as the first generation of IVF. If the man has severe oligospermia, the doctor in the embryo room needs to pick out the good sperm under a microscope and inject them into the matured egg cells by microinjection, which is also called microfertilization. After the fertilized egg forms an embryo, it is then transferred to the mother. This is often referred to as second generation IVF. There are two possibilities for men who have a semen test that suggests azoospermia. There is another kind of azoospermia, which is not really azoospermia, and sperm can be taken out from the epididymis or testicles, then we just need to take the second generation IVF, and the problem will be solved. There are couples who never get a baby, not because of infertility, but because of repeated miscarriages, and after examination, it is found that one of the couple has chromosomal abnormalities. There are also couples who have a genetic disorder in their family and are afraid to try to conceive. These cases can also be treated with IVF technology, where the eggs and sperm are combined in vitro to form an embryo and then a qualified embryo is selected using advanced experimental techniques and transferred to the uterus. The risk of miscarriage can then be reduced to ensure a healthy baby is conceived. This is what we call third generation IVF.