Assisted hatching is a procedure that consists of making a tiny hole in the zona pellucida of the embryo. The zona pellucida is the layer that protects the embryo like an outer shell. To implant, the embryo needs to break the zona pellucida and hatch naturally.
Sometimes hatching is performed with fragment removal. This method consists of extracting cytoplasmatic fragments through the hole that was made for hatching. These fragments are thought to interfere with the embryo’s cell junctions. This helps in making the cells more compact which is essential in the development of the embryo.
There is evidence that assisted hatching can help in the implantation process in some cases, for example, when the zona pellucida is hardened or in women over 40. Assisted hatching is not performed on all embryos because pregnancy rates are not increased, but selectively, the pregnancy rates do increase. Assisted hatching is performed minutes before embryo replacement.
