Assisted zona hatching

April 3, 2018

Assisted zona hatching (AZH) is one of the procedures in the assisted reproductive technology (ART). It is a procedure which is performed on the embryos before being transferred inside the uterus on the third day of its development. With the help of AZH, you will increase your chances of embryo implantation and further, pregnancy.

The human embryo is amidst a shell-like structure known as zona pellucida. The embryo must come out of this shell for the binding to occur correctly. However, if the shell is extremely hard or thick, it becomes difficult for the embryo to break out of it. Therefore, an artificial opening has to be performed on the shell for the implantation to take place.

When do doctors opt for Assisted Hatching?

Sometimes, the IVF procedure fails as the embryo shows the inability to latch itself in the uterus. This is frustrating and a disheartening experience for all the couples who must go through it. However, after a failed IVF, your fertility specialist might recommend assisted hatching.

What is Assisted Hatching?

After the egg extraction, it is fertilized inside the laboratory, where the cells start dividing. During this initial stage, the embryo is inside a layer of a protein known as zona pellucida. As mentioned earlier, for a successful implantation, it is necessary for the embryo to hatch out of the zona pellucida and implant itself on the wall of the uterus.

Assisted hatching is a new technique, which was developed when the doctors assess that the embryos sheltered under a thin shell of zona pellucida had better chances of implantation in IVF.


During assisted hatching, the embryologist will use a microscope for micromanipulation and make a small incision in the zona pellucida. This procedure takes place on the 4th day when the embryo has at least 6 to 8 cells. A small pipette is used to keep the embryo stable and on the opposite side, another small pipette with an acidified solution creates a small hole in the zona pellucida. Immediately after this step, the embryos are rinsed to avoid excess amounts of acid. Then they are first kept in an incubator and later transferred into the uterus.

Who is it for?

Assisted hatching is best suited for women with poor IVF results. To know more, you can visit your nearest Apollo fertility center and talk to qualified doctors for their opinion. This method is also useful for; women older than 36-37 years of age, women who have experienced failed IVF cycles 2-3 times, and for women who produce a poor-quality embryo.

Is it safe?

There are a few complications associated with assisted hatching as it can damage the embryo and can even damage individual blastomeres reducing the survival ability of the embryo. However, it is important to discuss it with your doctor and choose an expert fertility specialist.

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