In vitro fertilization experts will first cultivate the fertilized eggs to form blastocysts on the fifth or sixth day, and then classify them into grades, such as 5AA, 5BB, 5AB, 4AA, 4BB… So, what are the differences between different levels of embryos? Will there be any difference after the baby is born after transplanting 4AA and 5AA level blastocysts?
Will there be any difference after the baby is born after in vitro fertilization with 4AA and 5AA grade blastocysts?
American reproductive experts said: There will be no difference. For example, if you go to the hospital for a B-ultrasound examination at 20 weeks of pregnancy, the development size of each embryo will be different at this time. A fetus that develops quickly may be larger than the average fetal development at 20 weeks, and a fetus that develops slowly may be smaller than the average. Therefore, as long as the blastocyst grade is within a reasonable grade range, it is possible to successfully conceive, and there will be no health differences after the baby is born. It is very important that blastocysts of any grade must be diagnosed through genetic screening to ensure the health of the blastocysts.
So, what is the role of grading embryos? Next, let’s take a look at the analysis of American test tube experts.
The role of embryonic grading
According to American reproductive experts, embryo grading is an important standard for medical experts to superficially evaluate the quality of embryos in the form of morphological scoring and to initially screen high-quality embryos. This is mainly done by observing the speed of embryo development, the shape of the blastomeres in the embryos, and the quality of embryos. The number of fragments is divided into grades, such as 5AA, 5AB, 5BB, 4AA, 4AB and 4BB grade embryos.
The number represents the stage of the embryo, the first letter represents the mass of the inner cell mass, and the second letter represents the mass of the outer cell mass (ie, trophoblast cells), so the combined morphology of these blastocysts is:
5AA: The inner cell mass and trophectoderm are both very good and high-grade blastocysts that have begun to hatch. 5BB: A blastocyst with more cells in the core but not dense enough and few trophoblast cells. 4AA: Blastocysts with tightly packed cells, almost no debris, and not yet hatched. 4BB: A blastocyst with a large number of inner cells but few trophoblast cells.
Experts analyze that 5AA level embryos are the highest level. Because the embryonic cells at this level have begun to hatch, they are of high quality and have strong vitality and strong development potential. Therefore, the higher the embryo level, the better the quality.
In vitro fertilization does not mean that the higher the grade of embryos transferred, the higher the pregnancy rate.
American test tube experts said: Because the classification of embryos is only a preliminary assessment of the quality of the embryos based on their morphology, and cannot detect the genetic material of the embryos, it cannot ensure whether they are healthy. If a dolphin fetus with chromosomal abnormalities is implanted into the uterine cavity, even if it is high High-grade blastocysts cannot implant smoothly, or may cause fetal arrest and miscarriage in the later stages.
Therefore, in vitro fertilization does not mean that the higher the grade of embryos transferred, the higher the pregnancy rate. The two are not directly proportional.
At the American Reproductive Medical Center, experts will use third-generation in vitro fertilization technology to conduct genetic testing on embryos before transplantation, and then select embryos with high health categories for transplantation. This can improve the success rate of female pregnancy and protect the health of offspring. Realize eugenics and eugenics.
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