Thinning a portion of the outer embryo shell by a laser for facilitating embryo’s hatching process.
On the 5th or 6th day of its development, the embryo leaves its protective outer layer (zona pellucida), which among other things has protected it till now from extracorporeal manipulation. This process of breaking out or “hatching” is necessary for the embryo to establish contact with uterus cells in which it becomes implanted.
Some embryo implantation problems in patients with recurrent implantation failure may be explained by the inability of the embryo to hatch out of its zona pellucida. This may occur naturally or hardening process can arise after vitrification. In such cases, zona pellucida can be thinned in one part using the laser technique to improve the pregnancy, implantation and delivery rates . LAZT offers many advantages over traditional assisted hatching (AH).
Mainly, it does not involve opening of the protective layer and internal environment of the embryo remains intact. The risk of immunosuppressants from white cells and any local inflammatory are more harmful to the blastomeres of total zona pellucida assisted hatching. Furthermore, LAZT is not associated with an increased rate of identical monozygotic twins as opposed to zona opening methods.
There is no need of concerns about using laser since the target in reaction process is controlled accurately and has been shown to have no mechanical, thermal or mutagenic effect.