The outer membrane of the egg (zona pellucida or egg shell) protects the egg and then the embryo during the first days of its life, from the external environment. Usually two to three days after embryo transfer, the zona pellucida is dissolved and the embryo is released and then implanted in the endometrium. When the zona pellucida is very solid, the embryo cannot be easily released. In this case, prior to embryo transfer under the microscope, a hole is made in the zona pellucida (Assisted Zona Hatching), now with the use of LASER in our Centre. This technique helps the effectively release of the embryo into the uterus, thus increasing the chances of success. It is used mostly in the cases of very thick zona pellucida or when a couple has tried in vitro fertilization and embryo transfer many times yet with unexplained failure.
With this procedure, the embryo is artificially helped in being released from the zona pellucida in the laboratory and during embryo transfer at the blastocyst stage, to enter the endometrium for implantation unobstructed.