Some researchers believe that the possible reason for the failure of implantation of the embryo with assisted reproductive technology, may be the difficulty of hatching the embryo from the shell. Before an embryo can implant into the lining of the uterus it must ‘hatch’ out of this shell. This usually occurs five or six days following fertilization. The reason for this is that zona pellucida (the outer shell of the embryo) is thicker or stronger than normal. Laser-assisted hatching is a laboratory procedure that is intended to help the process of hatching the embryo from the shell, for which is performed a small notching using a laser.
Laser-assisted hatching is one of several methods to help the embryo hatch and attach to the womb. Other methods are acid or mechanical hatching of one a part of zona pellucida.
The most up-to-date method is an exploitation of a laser beam, which allows you to make a high-precision incision of the desired size. The procedure has no negative effect on the embryo itself. Laser hatching is done only on the shell of embryos, which are intended for transfer. To do this, on the third day of cultivation, the embryo is captured with a holding micropipette and a high-precision laser makes a small hole in the outer part of its shell. After this, the cultivation of embryos continues in the usual mode until the moment of transfer.
When can laser hatching be used?
♦ For women over 38 years old, because of the age zona pellucida thickens and becomes harder.
♦ Patients with previous unsuccessful IVF attempts of the transfer of good quality embrio.
♦ For cycles with cryoembrio transfer since it is known that zona pellucida becomes tougher after freezing with subsequent defrosting.
♦ Patients with elevated FSH levels.
♦ Women who naturally have eggs cells with a thick zona pellucida.
Laser hacking is practiced in leading reproductive centers around the world. Researches published over the past 10 years have suggested that using the procedure increases the chances of a pregnancy (for patients who have indications for this procedure). There is no data on the negative effects of laser hatching on the outcome of a program of infertility treatment.