The medical name for IVF is in vitro fertilization-embryo transfer (IVF-ET for short). It is a procedure in which the eggs and sperm of an infertile couple are removed from the body, fertilized and developed into day 3 or day 5 embryos in an artificially controlled in vitro culture system, and then the embryos are transferred into the uterine cavity. The earliest in vitro fertilization-embryo transfer technique, the first generation IVF technique, refers to the process of removing eggs from a female patient, fertilizing them with sperm in an in vitro culture, and then transferring the embryos that have reached a certain stage of development in vitro into the uterine cavity of the woman to allow them to implant and develop into a fetus. The first generation of IVF technology is mainly applicable to: 1. the female side due to tubal factors: tubal obstruction, hydrocele, tuberculosis, post-surgical ligation or congenital tubal defects; 2. patients who are infertile one year after tubal recanalization, plastic surgery and pelvic adhesion decomposition; 3. unexplained infertility; 4. immune infertility: the presence of anti-sperm antibodies in the semen of the male side or cervical mucus of the female side; 5. ovulation disorder drug treatment Those who are ineffective: such as polycystic ovary syndrome; 6. Endometriosis: those who are ineffective with medication or surgery; 7. Oligospermia or weak spermatozoa in the male partner: those who are ineffective with treatment; 8. Patients who have failed AIH for 3 or more times. However, for patients with azoospermia or severe oligo-, weak- and teratozoospermia, the sperm count is too low to meet the requirement of sperm count for in vitro fertilization, and the first generation of IVF technology will not be able to help. Therefore, these people have to resort to the second generation IVF technology, namely intracytoplasmic single sperm injection (ICSI): ICSI means that the relatively “robust” and “perfect-looking” (more normal morphology) sperm are selected through extremely fine glass needles under microscopic magnification. ICSI is a technique in which a relatively “robust” and “perfect-looking” (normal morphology) sperm is selected and injected directly into the oocyte plasma under microscopic magnification to form a fertilized egg. To put it bluntly, this is a “pulling and matching” process. This technology can also be used for patients with obstructive azoospermia, sperm acrosome abnormalities, IVF fertilization failure. the indications for ICSI, in addition to the less weak and teratogenic sperm evidence just mentioned, are: 1, severe less, weak, teratogenic sperm; 2, irreversible obstructive azoospermia; 3, spermatogenic dysfunction (excluding genetic defects due to disease); 4, immune infertility; 5, IVF-ET fertilization failure or In vitro fertilization rate <30%; 6. Sperm acrosome abnormalities; 7. Pre-implantation embryo genetic examination is required. But what about patients who may have genetic diseases? This requires a third generation technology, the third generation IVF technology, namely preimplantation embryo genetic diagnosis (PGD). It is mainly used for patients with genetic disorders such as hemophilia and thalassemia. It is when the embryo develops to 6-8 cells, 1-2 of them are removed for chromosomal examination and chromosomally normal embryos are selected for implantation into the woman's uterus.