I often have patients come to me with pictures of embryos and ask: Doctor, can you help me see if this embryo is good or bad? Is the embryo good or bad? It seems to be a simple question, but in fact, this question can put all the embryologists in the world down. IVF technology has been developed from scratch, from scratch to fine, and to this day, there are still a large number of scientific elites who are investigating this issue, although we are approaching the truth step by step, but the truth is still like a fog. First of all, the embryo that we put into the uterus is only an embryo that has been developing for three to six days, but the whole growth and development of the fetus takes “October” to ripen, and on the third day I have to judge whether the embryo is good or bad? It’s like running a marathon, the gun has just gone off and you’ve only run a few hundred meters, and you want someone to tell you who came first, who came second, and who came last? Is there no way to tell then? No! In the case of the marathon, although I can’t tell the final result precisely, I can predict it with some accuracy based on each runner’s past performance and status. The same is true for embryos, although we have to make a judgment on the third day, we embryologists have really developed a pair of wise eyes to see through the surface and predict the future developmental trajectory of the embryo from the early three days of development, as the saying goes, “the age of three is 80”, there are certain rules to follow. The following terminology is quite complicated. The following terminology is too much, so you can bypass it if you don’t understand it! The human egg starts to divide 24-30 hours after fertilization, a cell divides into two, and each cell of the embryo has a special name called the cleavage ball. Recent studies have shown that the developmental potential of embryos decreases if their early division rate is slower than normal. Therefore, a 4-cell embryo with uniform cell size on day 2 is a good quality embryo; an 8-cell embryo with uniform cell size and little debris on day 3 is a good quality embryo; a good quality embryo on day 4 is a mulberry embryo; an embryo on day 5 should develop into a blastocyst; and a blastocyst hatches from the zona pellucida on day 6. Early embryo division is either too fast or too slow, indicating some abnormality in the embryo. If you didn’t understand the above paragraph, it doesn’t matter, it simply means that an embryo that develops to a normal cell count at the right time —- is probably a good embryo! Why do we need to add the word “likely”? It means that although there is a lot of data to support this “appearance-based” method, it is not 100% accurate, and an embryo that looks good on the surface may be just an “embroidered pillow”. It is possible that the embryos that look unattractive on the surface may be a dark horse! So what can be done to improve the accuracy rate? Running a marathon, a few hundred meters when predicting the result is a little difficult, if you run a few kilometers and then predict it? Wouldn’t it be more accurate? The same is true for embryos. If the accuracy of the embryos selected on the 3rd day is not too high, let the embryos develop for a few more days to the blastocyst stage, and then select the embryos again, the accuracy will be higher naturally! These methods, of course, are fundamentally predictive by looking at the appearance of life, which is as complex and inscrutable as it is, and we have no way to get to its root. Scientists are still working on some new methods to predict whether the embryo is good or bad, hoping that it will be quick and easy without damaging the embryo, but of course, there is no method that can achieve such satisfaction yet. What is a good embryo? Practice is the only standard to test the truth, and the embryologists have to put the “good” embryos into the uterus and wait for the test of practice to determine whether they are good embryos or not. The embryologists at the Fertility Center of Zhongshan Sixth Hospital have a pair of discerning eyes, and the embryos they select will have a high degree of conformity with the test results, so that your dreams can be fulfilled!