What is assisted hatching ?
Some studies have suggested that a possible reason for the failure of implantation following IVFtreatment may be the inability of the embryo to undergo this hatching process. This may be due to the zona pellucida (the outer wall of the embryo) being thicker or harder than normal. Assisted hatching is a laboratory procedure first developed in 1990. It is designed to assist in the hatching process, where a small hole is drilled into the zona of the embryo. This used to be achieved by localised exposure of the zona to an acidified enzyme solution. Nowadays a precise laser beam is used to make a precision opening of the required size. The procedure does not have any adverse effect on the embryos themselves
What is involved?
The embryos are cultured to day 3 (i.e. 6 to 8 cell stage) and the best 2 (or 3 for some women over 40) embryos selected for transfer. Assisted hatching will only be done on embryos designated for transfer. The embryo is held in place using a holding pipette and a small precision opening is created in the zona using a laser beam. The embryo is then cultured until the time of embryo transfer.
Who may benefit?
- Women over the age of 38 years, as it has been shown that zona tend to thicken and harden with age.
- Patients with a history of previous failure to become pregnant following IVF with good quality embryos.
- Frozen embryo replacement cycles, as it has been shown that zona tend to harden during the freezing and thawing process.
- Patients with increased FSH levels.
- Women who have eggs with thick zona.