There is always such a category of couples who receive IVF-ET assisted conception with repeated implantation failures. In order to help these couples jump out of the IVF-ET cycle to report their babies home as soon as possible, a new technology – assisted hatching – was recently introduced in the Reproductive Center of Changhai Hospital. Today, we will unveil the magic of assisted hatching with you. When the word “hatching” is mentioned, what comes to mind most often is the exciting moment when a chick breaks its shell. Today we are talking about assisted hatching in the field of assisted reproduction, which is the microscopic manipulation of the embryonic zona pellucida to create a hole in the zona pellucida or to reduce the thickness of the zona pellucida so that the embryo can be easily hatched out of the zona pellucida. First, let’s understand the zona pellucida. The zona pellucida is a non-cellular structure that surrounds the oocyte (yellow area above) and plays an essential role in the entire process of ovulation and fertilization of the ovum. It protects the oocyte from harmful substances, assists sperm penetration during fertilization and prevents multiple sperm fertilization, and ensures the integrity of the embryo during oogenesis. Under normal circumstances, the zona pellucida thins gradually as the embryo divides the egg. Upon entry into the uterine cavity, the embryo breaks through the zona pellucida and escapes (i.e., hatching), after which implantation begins, due to a complex and miraculous set of factors. Therefore, any abnormality of the zona pellucida (loss of elasticity, hardness or thickening, etc.) will prevent hatching, which will prevent the embryo from implanting in the uterus and eventually lead to pregnancy failure. Obviously, it makes little sense to provide assisted hatching for embryos that hatch normally on their own, but assisted hatching for embryos that have difficulty hatching on their own can help to increase the rate of embryo implantation and thus increase the clinical pregnancy rate. Therefore, we recommend assisted hatching for couples with the following conditions 1. elevated basal FSH levels 2. advanced age 3. repeated implantation failures of unknown origin, excluding endometrial and embryo quality factors 4. frozen resuscitated embryos 5. microscopic abnormalities of the embryonic zona pellucida 6. low quality embryos 7. embryo fragmentation >20% 8. preimplantation genetic screening or diagnosis Regarding the safety of assisted hatching, no adverse effects of assisted hatching on embryo development have been found. adverse effects on embryo development. However, it should be emphasized that assisted hatching can improve the clinical pregnancy rate to a certain extent, but it is still possible that assisted hatching may help pregnancy failure; and assisted hatching may increase the probability of monozygotic twins. Together, we believe that the new technology of assisted hatching will bring good pregnancy to some couples.