Assisted hatching: facilitating embryo implantation

An embryo is covered by a protective layer (zona pellucida) in the early days of its development. The process of embryo implantation begins on the fifth or sixth day after fertilisation, when the embryo leaves its protective shell, the zona pellucida disappears and embryo cells come into direct contact with the cells of the uterine lining, which means the elimination of the mechanical barrier impeding further growth of the embryo.

Assisted hatching is primarily used in cases of recurrent implantation failure.