Assisted hatching is a relatively new technique used during certain IVF procedures. It is performed in order to help an embryo hatch out of its protective layering and implant into the uterus.
During the initial stages of development, embryo is contained in a layer of proteins, known as the zona pellicuda. The zona pellicuda is designed to protect the embryo until it reaches the blastocyst stage of development. In order to successfully implant into the uterine lining, the embryo needs to hatch out of this zona pellicuda and attach to the walls of the uterus.
Sometimes, embryos have a difficult time hatching out of their protective layer. This can occur if the zona pellicuda is too thick or if the embryo does not have enough energy to break through the layer. Assisted hatching attempts to help these embryos break out away from the zona pellicuda by creating a small hole in this outer lining.
Assisted hatching is a very delicate procedure, requiring immense skill. It is performed using micromanipulation techniques, under a microscope, during the fourth day of embryo development.
The embryo is first placed in a petrie dish containing culture solution. A special pipette is then used to hold the embryo in place. The embryologist takes a hollow needle that contains an acidic solution and places it next to the zona pellicuda. A tiny bit of this acidic solution is released from the needle so that it comes into contact with the zona pellicuda. This acidic solution begins to slowly digest the protective layering, creating a small hole. The embryo is then washed in a special solution and placed back inside an incubator until embryo transfer can take place.
Assisted hatching techniques aren’t suitable for every couple. Instead, the procedure is typically recommended for:
- women over the age of 37
- women with elevated FSH on day 3 of their menstrual cycle
- couples who have experienced failed IVF cycles
- couples whose embryos have a particularly thick zona pellicuda