The female oocyte is surrounded by a membrane, the zona pellucida (transparent zone), which allows a single sperm cell to enter and fertilise it. Following fertilization, the zona pellucida surrounds the embryonic cells at the early stages of cell division.
The zona pellucida becomes more resilient (hardening) as the embryo develops in the laboratory (quite possibly for reasons of protection). However, there are other factors which contribute to the same result, including the woman’s age (over 37 years of age) and poor ovarian response, which make an increased daily dose of gonadotropins during ovarian stimulation necessary.
The problem caused by the hardening of the zona pellucida is the embryo’s possible inability to hatch, namely to exit the zona pellucida and implant itself in the uterus.
This exact problem is addressed by the laser assisted hatching technique. The embryologist creates an opening in the zona pellucida, thus enabling the embryo to complete the hatching process and implant itself in the uterus.
The technique of assisted hatching has been found to increase success rates of female infertility treatments. At Mitera-IVF we implement this laser technique which, compared with previous techniques, has ensured greater accuracy and speeded up the process of hatching, so that the embryos remain outside the incubator for a shorter period of time.