Blastocyst Transfer

What is Blastocyst Transfer?

Blastocyst transfer is a modern and effective method used in IVF treatment. This process is carried out by placing the embryo fertilized in a laboratory environment into the uterus on the blastocyst stage, which is the 5th day of the developmental process. The main reason for preferring blastocyst transfer is that the embryo that reaches this stage is genetically healthier and potentially stronger.

The blastocyst stage, which is a critical stage in the development of the embryo, covers a period when the embryo divides into approximately 200-250 cells and separates into inner and outer cell masses. The importance of this stage is that it is the stage where the embryo has the highest chance of attaching to the inner lining of the uterus, namely the endometrium. In natural pregnancies, the embryo successfully settles into the uterine wall at this stage and the pregnancy process begins.

Blastocyst transfer stands out as a method that increases the chance of pregnancy, especially in couples who have not received positive results in previous IVF attempts. During this process, the embryo is monitored in a laboratory environment until the 5th day stage and its development is monitored. Embryos with the highest potential for success are selected and transferred. Embryos that reach the blastocyst stage generally have a higher implantation rate. This may mean an increased chance of pregnancy.

Blastocyst transfer is also important because it ensures that the embryo is synchronized with the uterus. In the natural cycle, the embryo settles into the uterine lining at the blastocyst stage within a few days after reaching the uterus. In IVF treatment, this natural process is imitated to try to increase the compatibility between the uterus and the embryo.

Who Can Have Blastocyst Transfer?

The blastocyst transfer method, which is frequently used in IVF treatment, is considered more suitable especially for certain patient groups. Blastocyst transfer is preferred to increase the success rate of IVF treatment in women over the age of 35. Transferring the embryo at a more advanced stage can increase the likelihood of pregnancy.

In couples experiencing repeated IVF failures, blastocyst transfer is considered an alternative option. This method allows for the selection of healthier embryos after previous unsuccessful attempts.

At the same time, blastocyst transfer can be applied to patients with good quality and number of embryos. This helps to select the healthiest embryo and increase the success of the transfer.

Blastocyst transfer can also be preferred in cases where genetic screening is required. Because biopsy performed at the blastocyst stage provides more reliable results for genetic examination. If embryo freezing is planned, this method can be chosen because blastocyst stage embryos give better results. Embryos frozen at the blastocyst stage have higher survival rates after thawing.

What are the Advantages of Blastocyst Transfer?

As we mentioned before, the 5-6 day old embryo is called a blastocyst. Normally, 2-3 day old embryos have not yet completed their journey from the fallopian tube to the uterus. The embryo usually begins to attach to the uterine wall on the 5-6th day.

Blastocyst transfer is performed in order for the pregnancy process due to in vitro fertilization treatment to be as close to a natural pregnancy as possible. In this way, the chance of pregnancy can be increased. Since the cells in the embryo begin to divide and multiply rapidly while it is at the blastocyst level, there are approximately 120 cells in the embryo during the blastocyst period.

A few days after the blastocyst transfer, the process of attachment to the uterine tissue begins with the emergence of the protective layer called “zona pellucida” around the embryo. In our country, the fact that a maximum of 2 blastocysts can be transferred at the same time also prevents the risk of multiple pregnancies.

Blastocyst transfer can be performed extremely easily. When the embryo is transferred on the 3rd day, it needs to be left in the fallopian tube, whereas in blastocyst transfer, the embryo is directly placed in the uterus. In addition, the probability of pregnancy is higher.

Another important advantage of blastocyst transfer is that much more consistent and accurate results can be obtained from genetic tests in implantations performed during this period. Thus, higher quality embryos can be transferred and babies born can open their eyes to life in a healthier way.

The development of 2 or 3-day-old embryos transferred sometimes stops as of the fifth day. Accordingly, in vitro fertilization treatment results in failure. There is no such risk in blastocyst treatment.

On the other hand, the biggest risk of blastocyst treatment is that none of the eggs fertilized in the laboratory reach the blastocyst stage. In couples who encounter such a situation, embryo transfer is usually performed on the 3rd day in their next attempt. It may be possible for embryos that remain in the culture medium for less time to experience less stress and continue to develop in the uterus.

What are the Blastocyst Stages?

The blastocyst stage, observed approximately 5 days after fertilization, is an important turning point in the development of the embryo. This stage is a complex and dynamic stage of embryo development and involves the embryo beginning to differentiate structurally and functionally. Understanding the blastocyst stages is very important for embryo development and therefore for a successful pregnancy.

In the first few days after fertilization, the embryo constantly divides to form a dense cluster of cells called the morula. In the blastocyst stage, which comes after the morula stage, the embryo now develops into a more sophisticated structure. At this stage, the embryo separates into two basic cell groups, the inner and outer cell mass.

One of the characteristic features of the blastocyst stage is the formation of a fluid-filled cavity, the blastocele, inside the embryo. The blastocele helps the embryo maintain its structural integrity and support cellular differentiation. This fluid-filled cavity facilitates the transport of nutrients and signals between the inner and outer cell masses of the embryo. Thus, it provides the environmental conditions necessary for the development of the embryo. The blastocyst stage is the period when the embryo has the highest chance of attaching to the endometrium, the inner lining of the uterus.