There is always a category of couples who undergo IVF assisted conception where embryos repeatedly fail to be implanted. In order to help these couples jump out of the IVF cycle as soon as possible and bring their daily babies home early, a new technology – assisted hatching – has been launched at the Center for Reproductive Medicine of Changhai Hospital recently. Today, we will unveil the mystery 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 out of its shell. Today we will talk about assisted hatching in the field of assisted reproduction, which is similar to “chicks breaking their shells”. —— makes it easier for embryos to hatch from the zona pellucida by making holes in the zona pellucida or thinning the zona pellucida through microscopic manipulation techniques. Let’s first understand the zona pellucida. The zona pellucida is a non-cellular structure that surrounds the outside of the oocyte (yellow area above) and is integral to the entire process of ovulation and fertilization of the egg. 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 zona pellucida 6. low quality embryos 7. embryo fragmentation >20% 8. preimplantation genetic screening or diagnosis Regarding the safety of assisted hatching, the following is explained: no adverse effects of assisted hatching on embryo development. However, it should be emphasized that assisted hatching can improve the clinical pregnancy rate to a certain extent, but there is still a possibility of pregnancy failure; and assisted hatching may increase the probability of monozygotic twins. Together, we believe that assisted hatching is a new technology that will bring good pregnancies to some infertile couples.