[Assisted hatching and micro-fertilization]

Erbium-YAG laser has been applied for micromanipulation in human beings. In a first series of attempts it was used in the fertilization process for subzonal insemination (SUZI): laser assisted micromanipulation achieved significant higher fertilization rates (34.8%) when compared to mechanical SUZI (16.1%), and for partial zona dissection (PZD): in this case laser did not improve the results (laser 14.8% vs mechanical 14%). Erbium-YAG laser was used to assist hatching. In the mouse it significantly improved the hatching rate (80% vs 29.3%) 110 hours post hCG. This technique was applied in two different centres to patients with previous IVF failures. The implantation rate per embryo (14.4% laser assisted hatching vs 6% control group) and the pregnancy rate per transfer (40% vs 16.2%) were improved.