Assisted Hatching (AH)

Assisted hatching is when our doctors help embryo to hatch by making the shell of the embryo thinner or by making a small hole in its shell. A protein coat called the zona pellucida surrounding eggs and embryos helps to regulate fertilisation by preventing more than one sperm from penetrating the egg. It also acts as protection during the early stages of development.

However, for a blastocyst to implant into the endometrium and to establish a pregnancy, the embryo must first shed this coat, which it does usually on day six to seven of development naturally, this process is called hatching.

Assisted reproduction treatments most commonly fail after embryo transfer and this may be because the transferred embryos fail to hatch, perhaps because the zona is affected by cryopreservation (freezing) or in vitro lab culture.