Assisted hatching which is also known as ICSI or intracytoplasmic sperm injection, involves the insertion of a single sperm directly into a mature egg obtained from the ovary of a woman undergoing in-vitro fertilization (IVF). In-vitro fertilization involves mixing eggs with sperm in a laboratory. Egg fertilization happens when a sperm succeeds in penetrating the egg.
Throughout IVF, the fertilized eggs are observed for 3 to 6 days as they separate and mature into embryos. The best embryo can then be placed into the woman’s uterus in the hopes of helping her become pregnant or it can be frozen for future use.
While the embryo grows, it is encircled by cells that make up a protecting shell. The embryo simply breaks out of this shell as it grows. The expectation is that assisted hatching might help the embryo develop, implant into the uterine wall, and eventually direct to a pregnancy.
When should one opt for Assisted Hatching?
- Previous IVF cycles with failed implantation
- Women of advanced reproductive age
- IVF cycles involving pre-implantation genetic diagnosis
Methods used in assisted hatching
There are a few techniques available, and every embryo lab addresses this differently. The skill of the technicians saves the day for a thriving implementation of the below-mentioned methods:-
1. Mechanical hatching
In this technique, the embryologist keeps the embryo steady with the help of a pipette, while using a micro-needle to puncture through the zona pellucida, go just underneath the shell for a bit, and then come out the other end. (Imagine drawing a very thin line just alongside the embryo.)
Then, the area between the two punctures is gently rubbed until a small tear occurs. It’s difficult to control the size of the opening with this method.
2. Mechanical expansion of the shell
With this technique, the zona pellucida(the shell)is not broken open. Instead, hydrostatic pressure is injected just under the shell, to make it expand. The idea for this approach comes from the natural development of the outer shell throughout the hatching process.
3. Chemical hatching
This technique necessitates using a chemical identified as Thyrode’s acid. Tiny quantities of acid are applied to the zona pellucida until the shell is breached. Then, the embryo is quickly cleaned to avoid unnecessary acid exposure.
In the process of drilling, vibratory movements are used to create a conical opening. This technique uses something known as Piezo technology.
5. Laser-assisted hatching
The most recent of all techniques, in this method a specialized laser is used to breach the zone pellucida (shell)which is another possibility. Laser-assisted hatching provides much larger control of the extent of the hole formed, more so than mechanical hatching with a needle.
Assisted hatching is an evolving procedure that benefits a huge number of women nowadays. It is more often realized that assisted hatching may improve clinical pregnancy rates with patients who have experienced two or more failed IVF cycles or have poor embryo quality. Also, who are older than age 38. On the other hand, many doctors reveal a study that indicates that assisted hatching in a frozen embryo cycle may slightly decrease the odds of live birth.