Assisted hatching

• Hatching ( lysis of zona pellucida) is important so that the trophoectoderm cells interact with endometrial cells and implantation occurs.

• One of the reasons of failure of implantation is the inability of the blastocyst to lyse the zona pellucida (which protect the embryo after fertilization till it reaches the uterus).

• So techniques were developed in order to assist the embryo in zona pellucida lysis (assisted hatching): 1- Using acid Tyrode. 2- Mechanically using a micro needle. 3- Using laser assisted hatching.

• These techniques increase the pregnancy rates especially in these cases: 1- patient with previous implantation failure. 2- Frozen - thawed embryo transfer.