What is Hatching?
The unfertilized egg is surrounded by a shell. This shell is known as zona pellucida. This shell hardens after fertilization. This process is normal and it keeps the cells in the embryo together. The embryos have to break out of this shell to get implanted in the lining of the uterus. This breaking out of the shell is known as “hatching”.This happens around 2-3 days after the transfer of the embryo.
The shell hardens faster when sperms and eggs are cultured in a laboratory. Hence it is difficult for the embryo to get embedded in the endometrium. Without hatching the implantation fails and the pregnancy cannot be maintained.
Your doctor may recommend assisted hatching if you have:
• Advanced maternal age (>37 years old).
• Elevated Day 3 follicle stimulating hormone (FSH).
• Thick and/or abnormal eggshell.
• Poor quality/slow developing embryos.
• Embryos showing excessive fragmentation.
• 2 or more previous failed IVF cycles.
It was found that the embryos having thin shells get implanted easily. Assisted hatching is useful for the embryos which have a very thick shell around them. It leads to increased pregnancy chances. During this procedure, a small hole is made in the shell of the embryo to assist it to break out of it. This small hole is made with the help of a microscope on day 4 of the embryo life.
A laser has energy in its beam. This characteristic of the laser is made use of in this procedure. A beam of the laser is centered on the shell. It leads to the dissolving of the shell at that point or area around to create a hole. Through this hole, the embryo comes out resulting in hatching.
Assisted hatching improves IVF success rates. As embryo hatching is done, the implantation rate is increased and the rate of maintaining the pregnancy is higher.