Assisted Hatching is an assisted reproductive technology that can be sometimes done along with in vitro fertilization (IVF) treatment. It is usually recommended to the women who are facing unexplained IVF failure or for women with a poor prognosis. But Assisted Hatching is not recommended by the American Society of Reproductive Medicine (ASRM) as it hasn’t been shown to improve live birth rates and there are also additional costs and risks associated with this technology. There are many different methods available for Assisted Hatching that works differently. Each method involves their own pros and cons and the skill of the technician always matters a lot.
This method is also known as Partial Zona dissection.With the help of a pipette, the embryologist keeps the embryo steady. A micro-need is used to puncture through the zona pellucida to reach the shell for a bit and then come out the other end. After that, the space between the two punctures is softly rubbed until a small tear take place. But with this method, the control the size of the opening is bit difficult.
This technique involves using mouth controlled acid which is Tyrode on the external surface. Very small amounts of acid are applied to the zona pellucida until the shell is broken. Then the embryo is quickly washed to avoid the harmful effects of acid exposure.
Laser-assisted hatching offers more control on the size of the hole created than mechanical hatching with a needle. In this method, the Zona is pierced by using non-contact mode controlled by a computer. The special designed computer software enables more focus and measurement of embryos and find out a suitable position of embryos. For better performance three different laser intensities – low, medium and high are used.
This technique uses another technology something known as Piezo technology. It this technique vibratory movements are used to create a conical opening.
Assisted hatching by Pronase thinning of Zona pellucid:
In this technique, diluted solution of Pronase is used. The process is starts by transferring of embryos to Pronase diluted solution in the G2 medium. The main goal of this technique is to make thin ZP without removing it completely.
Of all the hatching methods, laser-assisted hatching may be considered as the safest and most effective. A Laser-assisted Hatching is more superior to chemical and manual hatching as it is a safe and gentle way to thin and weaken a small section of the zona pellucida which allow the embryo to hatch.It also offers many advantages including least handling of the embryo and giving fast and exact control over the entrance procedure. But chemical hatching is more commonly used hatching methods. The skill and experience level of the embryologist is an important factor responsible for the success of any methods.