In order to attach to the wall of the womb, an embryo first has to break out (hatch) from the gel-like shell that it is contained in. This shell is called the zona pellucida and is harder in some embryos than others. Assisted hatching is a procedure in which the zona (shell) of the embryo is opened using the techniques of Micromanipulation.
Assisted conception 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. To counteract this, assisted hatching aims to improve the chances of successful hatching by creating a hole in the zona pellucida. The use of assisted hatching results in higher pregnancy rates in selected cases.
Assisted hatching may be suitable for:
- Women who are over 39 years old and are using their own eggs
- Women who have had two or more embryo transfers without a pregnancy
- Women who have elevated follicle stimulating hormone levels (FSH)
- Women whose embryos appear to have unusually thickened zonae