ASSISTED HATCHING
During the blastocyst stage, that is, on the fifth day of embryo development (D5), a phenomenon known as hatching occurs. At this stage, the embryo attaches to the uterus and sheds a membrane known as the zona pellucida, whose function is to prevent other sperm from fertilizing the same egg and to keep the cells together.
There is a risk that hatching may not occur naturally in the uterus for various reasons (patients with a poor prognosis in treatment, advanced maternal age, embryos with a very thick zona pellucida, thawed embryos, etc.), which would make pregnancy completely unviable. In these cases, assisted hatching is recommended.
