Early human embryos develop within an outer covering called a zona pellucida. Before the embryo can implant in the uterus, the embryo must break through this covering. In some cases, it appears that human embryos sometimes lack the ability to do this.
The technique of assisted hatching involves measuring the thickness of the zona pellucida in embryos that are candidates for the procedures. If an embryo has not initiated the thinning process naturally, a small “window” is created in the wall of the protein coat. The embryos are then implanted normally into the uterine cavity.
You may be a candidate for assisted hatching if you are 38 years of age or older, or if you have previously had one or more IVF cycles with failure of your embryos to implant, despite otherwise good results.
This procedure allows couples the opportunity to limit the number of embryos transferred to the uterus and to freeze remaining embryos for later use. Cryopreservation may reduce the number of stimulations and retrievals necessary to achieve a pregnancy. It is important to note that not all embryos will be selected for freezing. Only those embryos that are viable and reach the blastocyst cell stage will be chosen for this procedure.