Laser assisted hatching
A shell called zona pellucida surrounds the unfertilized egg. The zona has an important role in fertilization as it allows only one sperm to penetrate the zona and enter the egg to achieve fertilization. After fertilization, at the cleavage stage of the embryo, the zona pellucida hardens. This is normal and serves to keep the cells in the egg together. To embed into the endometrium lining of the uterine cavity, the cells have to ‘hatch’ out of the zona.
When sperm and eggs are cultured in IVF laboratory, the zona pellucida hardens at much faster rate than in a natural cycle, making it more difficult for the embryo to implant. If this process is not completed properly, implantation failure occurs and a pregnancy cannot be achieved. Assisted hatching is the process of creating a hole in zona, to aid the embryo in the hatching process. A small infra-red laser beam is projected on the zona pellucida of the embryo and the zona is then vaporized or dissolved, creating a 10 to 20 micron hole. Laser Assisted hatching is done just before the Embryo Transfer and improves implantation and improves pregnancy rates.
Who might benefit from Laser Assisted Hatching?
- Women older than 37 years who have a tendency to produce eggs with a harder zona pellucida than younger women
- Women with a high Follicle Stimulating Hormone (FSH) level
- One or more unsuccessful IVF and ICSI cycles
- Embryo quality: Thick zona, slow or rapid cell fragmentation rate, frozen embryos with thick zona, thawed embryos