Assisted hatching of fertilized eggs: characteristics and advantages

Modern reproductive medicine offers a wide range of options for couples facing difficulties in conception. In some cases, the implantation of an embryo can be successfully achieved through a procedure known as assisted hatching of fertilized eggs. This procedure is particularly useful in situations where the thickness or rigidity of the zona pellucida prevents the natural emergence of the embryo, making it difficult for it to attach to the uterine wall.

Assisted hatching essentially involves reducing or opening a small opening in the outer envelope of the embryo, called the zona pellucida, to facilitate its exit and attachment to the uterus. Laser hatching, the most recent method, is highly precise, minimizes the risk of damaging the embryo, and reduces the duration of the procedure, making it the preferred choice of specialists.

What is the zona pellucida and what is its role?

The zona pellucida is a transparent membrane that surrounds and protects the embryo during the early stages of its development. During natural conception, the embryo itself emerges from this envelope before implanting in the uterine wall. However, in some cases, the zona pellucida may be too thick or rigid, posing an obstacle to successful implantation.

Assisted hatching allows this problem to be overcome. This procedure is particularly interesting for women of childbearing age, patients whose IVF attempts have repeatedly failed, and in cases where cryo-embryos are used, as freezing can alter the structure of the shell.

Hatching methods

There are several methods of assisted hatching:

• Laser hatching: the most modern method, which uses a laser to create a small hole in the zona pellucida. This method has the advantage of high precision, minimal risk of damaging the embryo, and a shorter intervention duration.
• Mechanical hatching: it involves the use of micro-instruments to stretch or cut the shell. This method is less common but remains effective.
• Chemical hatching: it involves the use of special acids to soften the zona pellucida.

Among all the methods, laser hatching is recognized as the reference technique due to its safety and effectiveness. Modern laser technology ensures strict control of the process and minimizes the risk of damaging the embryo.

Steps of the procedure

Assisted hatching is performed at the blastocyst stage, when the embryo reaches 5 to 6 days of development. The procedure is carried out in the laboratory before the embryo is transferred to the uterine cavity. The specialist creates a small opening in the zona pellucida, facilitating the exit of the embryo from the shell and its subsequent implantation.

Indications for assisted hatching

The procedure is recommended in the following cases:

• Women over 35 years old whose zona pellucida thickens with age;
• Patients whose implantation attempts have repeatedly failed;
• In cases of using cryo-embryos, whose shell structure may change after freezing;
• In cases of hormonal disorders making implantation difficult.

Does hatching increase the chances of conception?

Assisted hatching can significantly increase the chances of successful implantation. Studies show that women undergoing laser hatching have an additional 10 to 15% chance of conception compared to standard IVF protocols (in vitro fertilization). However, success depends on factors such as embryo quality, the woman's health, and the experience of the embryologist.

Possible risks and limitations

Like any medical intervention, assisted hatching carries risks. According to current research, serious complications are extremely rare (less than 1% of cases). The main risks include

• Minimal damage to the embryo;
• Risk of premature hatching of the embryo;
• Low effectiveness of the procedure if other factors are responsible for failure.

However, with modern equipment and highly qualified specialists, these risks are minimized.

Assisted hatching of fertilized eggs is an important tool in reproductive medicine, especially for patients at increased risk of implantation failure. Laser hatching, the safest and most effective method, increases the chances of successful conception.

To achieve the best results, the procedure should be performed in clinics equipped with modern technology and experienced personnel. If you have questions about the necessity of assisted hatching, contact a specialist at our NatuVitro clinic. They will conduct a thorough examination of your profile, assess the condition of your embryos, and propose an optimal treatment protocol considering your individual characteristics.