What is Assisted Hatching?

In order for an embryo to implant into the lining of the uterus, it must divide to the point where it forms a blastocyst (multi-cell embryo with a fluid cavity). The blastocyst is covered by a gel-like coating called the ”Zona pellucida" or “zona" for short. In order for the blastocyst to implant into the lining of the uterus, its cells must first break through the zona (a process called 'hatching'). In certain situations the ability of a blastocyst created by In Vitro Fertilzation (IVF) or IVF/Intracytoplasmic Sperm Injection (IVF/ICSI) to hatch is impaired.

Assisted hatching is a laboratory procedure whereby the zona of the early embryo is mechanically or chemically weakened in a way that assists the embryo to "hatch" from the zona more easily allowing implantation into the lining of the uterus. At the Centre for Fertility and Reproductive Health, assisted hatching is performed mechanically using a laser under high magnification. The laser is used to shave or thin the zona in one area of the embryo thereby creating an area of zona weakness to encourage the hatching process.

The assisted hatching technique was developed in 1990 by a team led by Dr. Jacques Cohen at Cornell University in New York. Since then many IVF centres have adopted this. Although there is some variability in results and technique, most studies on Assisted Hatching have demonstrated that it improves implantation rates in certain patients undergoing IVF and/or IVF/ICSI.
 

When should Assisted Hatching be considered?

Research suggests that Assisted Hatching may benefit:

• women 37 years or older; 
• women with poor quality embryos; 
• women who have had repeated implantation failures.