What is Assisted Hatching?
Assisted hatching is a micromanipulation procedure that is performed to assist an embryo in hatching out of its protective layering (called zona pellicuda) and implant into a woman’s uterus. To accomplish this, a small hole is made in the protective layer of the embryo. This method is used to improve the chances of success with in vitro fertilization (IVF). The technique was first introduced in the 1990s and is available at most fertility clinics throughout the United States.
During the initial stages of development, the embryo is contained in a layer of proteins that protects it until it reaches the blastocyst stage of development, which typically occurs after five days of fertilization. In order for the embryo to successfully implant into the uterine lining, it must hatch out of this protective protein layer 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 layer is too thick or if the embryo does not have enough energy to break through.
Assisted hatching can offer couples several advantages. Fewer embryos are typically needed for transfer, embryos can be transferred at the blastocyst (fifth day of fertilization) stage, and the success rate of implantation is increased with this procedure.
Who is a candidate?
• Women over the age of 37
• Women who have an elevation of a growth hormone (FSH) on day three of their menstrual cycle
• Couples who have previously failed IVF cycles
• Couples whose embryos have a particularly thick protective layer.
What is the procedure for assisted hatching?
Assisted hatching is performed during the third day of embryo development with the use of a microscope. The embryo is placed in a Petri dish and an acidic solution is injected via needle into the protective protein layer surrounding it. This solution begins to slowly break down the protective layering, creating a small hole. The embryo is then washed in a special solution and placed back inside an incubator until it is time for it to be transferred to the woman’s uterus.
What are the risks?
There are some risks associated with assisted hatching procedures. One of the greatest risks is the increased likelihood of identical twins. This is because the technique used to break through the protective protein layer of the embryo can sometimes cause the embryo to split into two identical halves. Other risks of assisted hatching include damage to the embryo, which can result in death, fetal complication, physical deformities and conjoined twins. The procedure takes immense skill and care by the technician as well.
Steroids and antibiotics that the mother must take to protect her immune system and prevent infection may create possible side effects as well. These include high blood pressure, infection, nausea, and mood swings.
What are the success rates for assisted hatching?
The success rates with assisted hatching are high – as high as 49 percent in women who are between the ages of 35 and 39 – particularly when the procedure is performed by a skilled technician. As with other forms of assisted reproductive technologies, women who are over the age of 40 tend to experience lower success rates. Still, assisted hatching offers older women a greater chance of conceiving via IVF than they would without the procedure.