Assisted Hatching
Author : Professor Eman Zein
• Updated at: Jun 09, 2024 •
Assisted hatching is a new lab technique that is used to increase the chances of fetus implantation in the woman's uterus. This procedure is based on the observation that embryos with a thin outer membrane had higher success rates of implantation. Therefore, embryologists decided to manipulate embryos before transferring to give them all this advantage. This procedure is now used alongside IVF/ICSI procedures.
What is Assisted hatching?
Assisted hatching is an additional process that can be used on embryos obtained through IVF and ICSI procedures to improve pregnancy rates under certain conditions. It is one of the Assisted Reproductive Technology techniques that enhances embryo implantation by hatching the zona pellucida. The Embryo is surrounded by a shell called the zona pellucida. For embryo implantation into the uterine lining to happen the embryo must break free of this shell. If the transferred embryo fails to due this it leads to IVF/ICSI failure.
To help the embryo “hatch” from its zona pellucida, doctors use the technique of assisted hatching to create a crack in the zona pellucida, so that the embryo gets out of the shell and increases the implantation chances. Assisted hatching methods are many, and we at Bedaya Hospital are using a laser-assisted hatching technique for it being more precise and effective.
How is assisted hatching done?
- After the egg has been fertilized by the sperm In an In Vitro Fertilization (IVF process), embryologists leave the fertilized egg in an Incubator to divide and develop into an embryo.
- On the third day after fertilization, a very small hole is made in the outer shell of the embryo “zona pellucida”.
- The embryo is transferred back to the woman’s uterus for implantations and hopefully a healthy pregnancy occurs.
The embryo may face some difficulties in hatching if having a hard, thick shell. the Assisted hatching technique effectively helps the embryo hatch properly and improve the odds of implantation.
Assisted hatching methods:
- Chemical hatching: this technique involves breaching the embryo’s zona pellucida with a specific chemical acid and rapidly washing it off prevent the embryo from acid exposure. This technique is common in most hospitals because it costs less.
- Laser hatching: this is the safest technique of assisted hatching using a laser to breach the zona pellucida, but not all hospitals are equipped with such technology.
- Mechanical expansion: this technique is more similar to the natural process of shell expansion. The embryologists expose the embryo’s zona pellucida to hydrostatic pressure to facilitate normal expansion.
Who should do Assisted Hatching?
As Assisted hatching increases the rates of a successful pregnancy it is a great technique for the following cases:
- Women who are older than 38 years.
- Couples who have been through failed IVF\ICSI procedures.
- Couples with low-quality embryos.
Assisted hatching is not recommended for all patients doing IVF/ICSI. It is recommended for a certain group of patients who have unexplained pregnancy failures after IVF/ICI cycles
Does assisted hatching improves IVF’s success rates?
Assisted hatching is a complex process that benefits those who priorly had failed IVF/ICSI procedure.
So, if the question is “does it improve IVF/ICISs success rates?” yes it does. It increases clinical pregnancy rates and improves Assisted Reproductive Technology (ART) success rates, but it does not increase live birth rates. However, the success of the procedure depends on the expertise and technique used by the embryologist. At Bedaya Hospital we have a team of embryologists that have been performing the procedure with great results for over 20 years.
Assisted hatching risks and possible problems
The risks of assisted hatching are very low. The main medical risk is an increase in identical twin pregnancies which couples often actually find to be an advantage.
Risks of assisted hatching
- Any embryos subject to manipulation are at risk. Assisted hatching may damage the embryo while breaching the shell of the zona pellucida. This damage may occur before or after uterine embryo implantation. In both cases, the pregnancy will fail.
- Sometimes the hatching processes causes an imbalance in the embryo and through some yet undefined defense mechanism the zona pellucida will not be breached.
- Twin pregnancy is considered a risk for some couples. Identical twin pregnancies show a slight increase after an assisted hatching process.
We would like to remind you that these risks are very rare, but we must explain the risks and possibilities of every procedure offered to our patients.
