The HLA-G method that has emerged in the field of in vitro fertilization, where new methods are discovered and implemented every day, is being debated as to whether it is really a miracle or just an application that promises unnecessary hope to patients. In this article, you can find experts’ evaluations on this issue.
The idea that in vitro fertilization treatment allows for the prediction of which embryo can successfully implant in the uterus and that this method can lead to increased pregnancy rates has garnered significant attention in both the press and medical circles.
Like many treatments for diseases, developments that are not yet certain about reproductive problems and are in the preliminary work and research stage are presented as a solution for patients. While these developments, seen as a new ray of hope by people who need treatment, create great excitement among patients, they often result in disappointment when put into practice.
What is the common method for embryo transfer?
Currently, the method generally used for embryo transfer relies on the shape characteristics and division rates of embryos. In addition, methods such as waiting for the embryos to be cultured in the culture medium until the 5th-6th day and determining the normal embryos as a result of genetic examination or determining the embryos with the highest development potential can also be used for selection. While applying all these criteria increases pregnancy rates, in some cases, the application may still not result in pregnancy.
What is the HLA-G method?
Some recent studies suggest that the secretion of HLA-G by embryos could be an important criterion in embryo selection. HLA-G is secreted by the embryo and is thought to prevent the rejection of the embryo by the mother’s immune system. Therefore, it is concluded that the likelihood of the embryo sticking to the uterus increases.
In summary, HLA-G prevents the recognition of the embryo by the mother’s cytotoxic lymphocytes and its destruction by natural killer cells.
According to the studies conducted, it is believed that HLA-G changes the Th1/Th2 balance in favor of Th2 during pregnancy and thus protects the embryo against the mother’s immune system. As a result of some research on this topic, it was observed that pregnancy rates significantly increased when some embryos that secrete HLA-G were transferred.
When looked at theoretically, HLA-G is thought to be a good criterion for embryo selection. However, there is not enough research on this issue yet. In the studies conducted, HLA-G secreting and non-secreting embryos were generally compared. As a result, it was seen that the pregnancy rates were higher in the group that secretes HLA-G.
The most important point that needs to be emphasized here is that during the studies, not only embryos that secrete HLA-G but also those that do not were transferred to most patients. Therefore, it is impossible to determine with certainty which embryo caused the pregnancy. To obtain definitive results, only one embryo should be transferred to patients, and the HLA-G-secreting group should be compared with the non-secreting group.
To summarize the results regarding HLA-G
In light of the research conducted on HLA-G, it can be said that it is a promising criterion for embryo selection, but it is still too early to make definitive judgments.
It is necessary to determine the relationship between embryo shape and division rates with research in addition to HLA-G secretion for embryo selection.
This method will not benefit patients who cannot get pregnant due to a shortage of eggs, as most of the embryos obtained are transferred to these patients. On the other hand, studies showing the superiority of selection criteria based on embryo shape and division characteristics for patients with many embryos need to be conducted.
This is because the pregnancy rates obtained by transferring HLA-G secreting embryos do not seem to differ from those of the good patient group who have a large number of embryos and who are selected with classical methods. For example, a pregnancy rate of 70% is already obtained in the patient group who are especially under 30 years old and undergo blastocyst transfer on the 5th day.
Research is needed to prove the selection criteria based on embryo shape and division rates and those based solely on HLA-G secretion.
In light of the studies conducted so far, it can be said that HLA-G is not the only criterion for embryo selection, but it can be used in addition to classical methods.