Assisted hatching

The basics

All human eggs, as well as embryos before implantation, are surrounded by a shell called the zona pellucida. During the so-called “hatching” of the embryo, the zona pellucida becomes thinner and opens, so that the embryo can emerge and then implant. This natural process is the result of several mechanisms.

Changes in the texture of the zona pellucida can prevent the fertilised egg from implanting

Culturing human embryos in the laboratory, even under the most favourable conditions, often leads to what is called “hardening of the zona pellucida”. In some embryos the zona pellucida is clearly thickened.
This may be linked to the woman’s age, high levels of FSH or the quality of the eggs themselves. The change in the zona pellucida leads to low implantation and pregnancy rates. Artificial “hatching”, which makes implantation easier, can overcome these problems.

What does assisted “hatching” achieve?

The technique was first performed by cutting through the zona pellucida, later with Tyrode’s solution and finally with a laser. All of these techniques help the embryo to emerge and to implant more easily. This results in higher success rates.

When does this technique make sense?

After several unsuccessful IVF attempts, despite the transfer of good-quality embryos.

Are there any risks?

As studies in laboratory animals and in humans have shown, these techniques appear to have no negative effect on the embryo, in contrast to eggs. Even so, in these pregnancies too we advise having all the necessary tests to rule out various abnormalities in the fetus.

What do the results show?

In a study of 300 patients who gave birth to 50 children after the laser technique, no problems have appeared in the children to date.
Also, in 100 births worldwide after various laser techniques, there was no increased rate of chromosomal abnormalities or birth defects.