In the process of IVF treatment, egg retrieval and embryo transfer, especially the transfer is the most concerned about the two parts of the embryo transfer is to wait nervously for the “lottery” process, but the success rate is not 100%, there are always a part of the people will experience hCG is very low or from the high and gradually reduced frustration and disappointment, why embryo Why do embryos fail to implant? Generally speaking, successful embryo implantation cannot be achieved without 3 conditions: acceptance of the embryo’s lining, embryo with developmental potential and synchronized development of the lining embryo. I. Embryonic factors Embryonic factors are the most common causes of implantation failure, and among them, embryonic aneuploidy, that is, chromosomal abnormalities and accounted for most of the time, at this time, you may want to ask: Why do you want to transfer chromosomally abnormal embryos? Because in the process of in vitro fertilization, we only rely on the development of the embryo and morphology to determine the embryo is good or bad, in this process, we can not screen out the embryo chromosomal abnormalities of the embryo. Here comes the question again: isn’t it said that chromosome screening can be done in three-generation IVF? First of all, not everyone can do three-generation IVF, only if they meet the conditions, secondly, three-generation IVF needs to cultivate embryos to the blastocyst stage, which is very difficult for some of those who have poor embryo conditions, and lastly, whether the test sampling is damaging to the embryos is still an unknown now, so it is necessary to screen those who meet the conditions with greater caution. In addition to the parents’ own chromosomal conditions, generally the older the mother the higher the probability of chromosomal abnormalities in embryos, so the pretreatment with drugs such as coenzyme Q10 and the application of growth hormone in the process of ovulation stimulation before in vitro fertilization are also aimed at improving the quality of the eggs and minimizing the probability of chromosomal abnormalities in embryos. Second, the uterus and endometrial factors The endometrium is the soil for the growth and development of the embryo, the endometrium is too thin, the endometrium is too thick, the endometrium is poor in morphology, the endometrium is poor in blood flow, the endometritis, the endometrial adhesion, the uterine fluid, the endometriosis, the adenomyosis, the uterine fibroids …… may cause the failure of embryo implantation, most of which we can find out in time by ultrasound or Most of these can be detected and dealt with by ultrasound or hysteroscopy, so the endometrial preparation program for each person is different, and perhaps the next transfer can be successful if the program is adjusted. Third, the mother’s own factors The mother’s health and the baby can grow up normally are closely related to the mother’s immune status, metabolic status are related to the growth and development of the embryo, so in order to obtain a successful pregnancy, mothers-to-be must have a healthy body, some auxiliary drugs, such as regulating the metabolism of insulin metabolism of metformin, to increase the level of vitamin D osteoarabinol and calcium tablets and other drugs are generally recommended to take long term before pregnancy, usually more exercise. Long-term use before pregnancy, more exercise in general, weight loss and lifestyle modification, these measures are not only to help the embryo implantation, but also to make mothers-to-be more healthy both in general and during pregnancy, to meet the arrival of a healthy baby in a better state.