Increasing IVF Success Rates: Assisted Hatching. Potential Benefits and Risks
Share This Article
Learn about donation options.
Subscribe our newsletter
to be notified when we publish
Assisted hatching is an additional assisted reproductive laboratory procedure being done in the laboratory. This procedure is performed in conjunction with the traditional in-vitro fertilization (IVF). The main reason for performing this procedure is the poor prognosis and the failure of IVF treatment with multiple attempts, and the reason is unknown.
This advanced reproductive procedure assists the implantation of the embryo. Using this procedure, the chances of conception and implantation rates are increased to a great extent.
IVF is the mixing of eggs and sperm outside the body of a female and then the implantation of an embryo or fertilized egg inside the uterus. In some cases, the process of IVF is not performed in the usual manner, and assistance is required. However, such treatment is not being done in all cases because of the associated risks along with the possible benefits. Following things are needed to be known if the doctor has recommended the assisted hatching.
Process of Embryo Hatching:
The knowledge of natural hatching is mandatory before getting to have an idea about assisted hatching. The egg is surrounded by the shell or an outer layer which is called zona pellucida.
The protein constituted zona pellucida has various important roles to play during the development of the embryo. Although, the roles do not remain the same and it tends to differ with the growth of the embryo.
The fusion of sperm cells with the zona pellucida takes place before the egg turns into an embryo. This fusion is considered the first step of the fertilization process. After the penetration of sperm cells and fertilization of the egg takes place, the “shell” becomes hard. The hardening of the shell prevents the further penetration of other sperm cells inside the fertilized egg. Moreover, it also prevents the premature implantation of embryos into the Fallopian tubes.
With the development of the zygote into the blastocyst stage, the zona pellucida starts to become thin and finally deteriorates. This step is embryo hatching. Around the fourth day of development, the protein shell cracks open, the embryo emerges from it while leaving the thin protein shell behind.
Within a few days of the hatching process, the implantation of the blastocyst into the endometrium is done. This hatching process is vital in making the pregnancy occur; otherwise, it fails to happen.
Assisted hatching is a new laboratory technique that is done on the third day of embryo development. A small tear or break is made in the zona pellucida that assists the hatching process. Research shows that the high chances of pregnancy to happen has an association with the thinner protein shell or zona pellucida.
The main cause of using assisted hatching is the improper hatching process of the embryo. The reasons for improper hatching are the unfavorable hatching environment of the lab, such as the chemical used for freezing or the cultures used for keeping the embryo alive has somewhat disturbed the environment which assists the hatching. Another reason is the unusual hardening of the protein shell. The inhospitable and unfavorable ovarian environment results in the thickening of zona pellucida or protein shell of the embryo, which in the end, causes complications in the pregnancy process.
To overcome all of these hurdles and to make the fertilization process go smoothly and successfully, assisted hatching is used. It improves the odds of implantation of embryos and increases the chances of conception.
Methods to perform Assisted Hatching procedure:
Certain methods are there which are in use for the hatching process. Every method has its own merits and demerits, and the success of each step depends upon the skills of technicians.
Few methods are as follows:
1. Mechanical Expansion of Shell:
In this method, the mechanical expansion of the shell is performed by applying the pressure under the embryo in such a way that it helps it to expand. This idea comes from the fact that the natural expansion of shells occurs in the hatching process.
2. Mechanical Hatching:
In this method, a microneedle is passed from one side of the shell to the other alongside the embryo while keeping it stable with the help of a pipette. This puncture is made very carefully.
Gentle rubbing of the area between two punctures is performed until a small tear or break occurs. However, the size of the tear is tough to control in this method.
3. Chemical Hatching:
In this method, the tear of zona pellucida is done using a chemical known as Tyrode’s solution. The acid in minute amounts is applied to the shell until breaches happen.
The quick cleaning of the embryo is done to protect it from further exposure to acid. This is one of the common methods performed in assisted hatching.
4. LASER Hatching:
Being the safest method in assisted hatching, laser-assisted hatching has advantages over other methods as the size of the break can be controlled easily. It is the most effective method. However, this is not being performed in every lab yet.
Ideal people for assisted hatching:
Assisted hatching is a technique that cannot be feasible to perform on every individual. It is recommended only in the women whose profile shows the issues in successful implantation.
Followings are the ideal candidates who get the maximum benefit from this technology.
- With at least 2 IVF failures in previous time.
- Age 37 or older
- Who has a thick shell around the embryo
- Women with poor quality eggs
- Women who use preimplantation genetic diagnosis during the treatment of IVF
- Whose eggs are frozen for preservation
Risks of Assisted Hatching:
Any kind of interference or manipulation with an embryo is associated with certain risks. One of the possible risks is that the embryo can undergo some lethal damage. This destruction can happen before or after the implantation of the embryo. In such cases, the pregnancy would not happen.
Assisted hatching also comes with another risk of twining. This twinning is specifically identical twinning that results from monozygotic twinning. This twining results from one sperm and one egg.
The risk of twinning has been greatly increased with the IVF treatment and the assisted hatching along with this conventional treatment may enhance the risks.
It is known that multiple pregnancies are associated with certain risks already. However, identical twinning has a greater risk both for babies and mothers. The risk of identical twinning is still very low.
Another possible risk that has a great association with the assisted hatching is congenital anomalies or birth defects. However, this is not only related to assisted hatching. Other factors also play a role in this regard.
Medicines such as steroids and antibiotics are prescribed when the days of embryo transfer and assisted hatching are around. These medicines have certain side effects on the whole process of fertilization and pregnancy.
The chances of embryo liveliness can be decreased because of the damage that can occur to it.
Since the assisted hatching in IVF procedure is a difficult step and comes along with certain drawbacks, it is important to discuss all the possible risks and complications with the doctor.
Benefits of Assisted Hatching:
The great concern in assisted hatching is whether it is effective enough to give benefits that are required. Studies have shown that the rate of clinical pregnancies has increased to a great extent. However, the rate of live birth rates does not show any improvement.
The main thing to ponder about is to take the baby home safely and not just get the pregnancy test positive. All along the fertility treatment is done to have a sound and healthy child.
In addition to this, the chances of pregnancy to happen in women with a poor prognosis can be enhanced by the assisted hatching. In women with a good prognosis, assisted hatching is not an option. The reason is that it will not only harm their good and functioning cells but it can also halt their natural process.
No concrete evidence is present about the success or failure of assisted hatching during the IVF treatment. It seems attractive to go through all the possible techniques and methods that come along with IVF treatment. However, more does not always mean right and effective.
Experts do not recommend assisted hatching in every single patient. If the clinic has a compulsion of using assisted hatching technique then must discuss it with the doctor the possible benefits of using it.
Discuss all of your situation and health condition along with the previous medical history while you are apt for IVF procedure and fertility treatments.
We are supporting women all around the world before, during, and after their pregnancy by providing up-to-date information and advice, and tools.
We kindly ask for your support to continue to produce content for you and to enable you.