Assisted hatching is a technology which helps embryos to attach to the womb of the woman. Pregnancy cannot occur unless the human embryo hatches.
The unfertilised egg is surrounded by a shell called zona pellucida. The zona pellucida ensures that only one sperm cell enters and thus fertilises the egg. After fertilisation of the egg, zona pellucida keeps the cells of the embryo together.
During the cleavage stages and in vitro culture of the human embryo, zona pellucida gets harder, possibly due to the culture conditions. Removing the egg for in vitro fertilisation and micro insemination takes it out of its natural environment. This procedure tends to lead to egg shells that harden faster than seen in vivo.
Especially women older than 37 years of age, have a tendency to produce eggs with a harder zona pellucida than younger women. The same applies for women treated with higher doses of follicle stimulating hormone (FSH).
The problem of a harder zona pellucida is that the eggs may not hatch or use excessive energy for getting out, thus not being able to attach to the woman’s uterus. Hatching of the egg is necessary to become pregnant.
Laser assisted hatching is one out of several methods to help the fertilised egg to hatch and attach to the uterus. Other methods are acid or mechanical hatching of one part of zona pellucida. At Copenhagen Fertility Center we offer laser assisted hatching, which is a gentle and safe way to weaken a part of zona pellucida. After treating the fertilised egg with laser assisted hatching, we transfer the embryo into the woman’s womb.
Recent meta-research (comparison of different relevant researches) showed that women who have undergone repeated IVF treatments without results, double their chances of a pregnancy by use of assisted laser hatching.