Hatching of the blastocyst is a critical component of the physiologic events culminating in implantation. Conversely, the failure to hatch may be one of the many factors limiting human reproductive efficiency. The clinical application of assisted hatching has been proposed as one approach toward the enhancement of implantation and pregnancy rates following in vitro fertilization.
The assisted hatching procedure entails the creation of a gap in the outer area of the embryo called the zona. This is done either by drilling with an acid medium, by laser, or by using a piezomicromanipulator.
Success rates following the use of assisted hatching in different ART programs have varied considerably. Well-designed studies suggest that assisted hatching might be best used in patients over 38 years old or with multiple prior failed IVF cycles.