Assisted hatching is the use of physical or chemical methods to create a defect or gap in the zona pellucida on the surface of the embryo to facilitate the emergence of the embryo from the zona pellucida, in order to facilitate hatching and implantation and increase the likelihood of implantation. What kind of patients are suitable for assisted hatching? A woman ≥ 35 years of age or with a basal FSH > 10 U/L; prior to frozen embryo transfer; history of repeated IVF treatment failure, excluding endometrial factors; thick or darkly colored embryonic zona pellucida;