After a few days of fertilization, the embryo is called a "blastocyst."
The embryo is called a blastocyst when five or six days have passed after fertilization . At that stage of development, prior to implantation in the uterus, it is a set of cells whose division takes place very quickly.
Internal mass and trophoblast
It is possible to recognize two kinds of cellular structures in the blastocyst. On one hand there is the internal mass that will allow the formation of the fetus, while on the other hand there is the trophoblast , a membrane that will give rise to the creation of the placenta . All of these cells are located in a fluid-filled cavity known as a blastocoel .
It is estimated that the blastocyst has about two hundred cells , with a size of two hundred microns. The embryo, in this phase, is already prepared to implant in the endometrium , the membrane that lines the uterine cavity.
Blastocyst culture
Blastocyst culture or blastocyst transfer is a resource used in in vitro fertilization . The technique is carried out when, once the follicular puncture has been performed, the embryo is preserved under special conditions in the laboratory until it reaches the fifth or sixth day of development: that is, until it reaches the blastocyst stage.
According to specialists in assisted reproduction , the transfer of a blastocyst to the uterus offers greater effectiveness in terms of achieving pregnancy than the transfer of embryos at a previous stage. Precisely, it promotes the selection of the best embryos so that they can then be implanted, enhancing the chances of a successful pregnancy. In addition, it reduces the possibility of multiple gestations.
This procedure must be done in an in vitro fertilization laboratory (which is usually abbreviated as IVF) , using incubators that have this specific application to carry out the control and optimization of all the properties necessary for the embryos to develop correctly. normal until the blastocyst is formed.
It is important to note that, in the laboratory , there are embryos that fail to reach the blastocyst stage. That is why it is not always considered advisable to wait five days before making the transfer.
Complications in its development
The first of the problems that can prevent the completion of the preparation of the blastocysts for their subsequent transfer, in addition to causing their deterioration , is the stress that the embryos may suffer during the first days, while they are in the laboratory.
Another factor that can negatively impact this aspect is the quality of the sperm : if it is not good enough, it can prevent the embryo from becoming a blastocyst. For this reason, doctors must offer a responsible diagnosis that results in the best possible treatment for each patient. Sperm banks usually impose very strict controls before accepting samples, so their reliability is good.
Finally we can mention the quality of the egg , since the development of the embryo also depends on this factor. It should be noted that the woman's age is directly related to this, although this is not a golden rule. In the most prestigious blastocyst culture processes, donors also go through very demanding selection filters to guarantee the best results.
Blastocyst culture has a high success rate
Advantages of blastocyst culture
Let's summarize the advantages mentioned so far and add others:
* more effective selection of embryos;
* higher chances of successful fertilization;
* the embryo and the uterus are found in the same way as in natural fertilization;
* embryos that cannot be implanted are not transferred ;
* It is possible to avoid multiple pregnancies, either by the patient's wishes or due to medical contraindications.