The main factors that determine the success of IVF are the quality of the embryo, the tolerance of the endometrium and the synchronization of the two. Like the relationship between the seed and the soil, where the embryo is the seed and the endometrium is the soil, the synchronization of the two is the right time to plant the seed. In addition, personal health, psychological factors and the transfer process also play a big role in improving the success rate of IVF. I. Embryo quality Currently, the assessment of embryo quality is mainly carried out by observing the morphology and development rate of embryos, which is a simple, easy and non-destructive method. However, the accuracy only reaches 60-70%. It is generally accepted that 46-48 hours after insemination and development to the 6-8 cell stage is the normal rate of embryo development. Before transferring embryos, doctors will consider the quality of embryos and select embryos with high developmental potential for transfer, but at the same time, they will limit the number of embryos transferred to avoid the occurrence of multiple births. Wang Kehua, Center for Integrative Reproduction and Genetics, Affiliated Hospital of Shandong University of Traditional Chinese Medicine To improve the quality of embryos, it is necessary to start with improving the quality of eggs and ovaries, conditioning the bodies of both partners is fundamental, having good diet and lifestyle habits, and necessary nutritional supplements to enhance fertility. Endometrial receptivity The endometrial receptivity is the acceptability of the endometrium to the embryo. The successful establishment of endometrial receptivity during embryo implantation is an essential factor to ensure successful embryo implantation. The indicators commonly used by physicians for evaluation are endometrial morphology and subendometrial blood flow assessment under vaginal ultrasound. Pre-transfer hysteroscopy can also rule out abnormal endometrial lesions. In patients with high embryo quality who are not able to have a successful pregnancy after transfer, hysteroscopy is recommended in this group of patients to exclude uterine cavity pathology. III. Embryo transfer Transfer of day 3 embryos or day 5 blastocysts requires the embryos to be cultivated in vitro at a time that matches the time of endometrial transformation and transferred during the implantation window of the endometrium to improve the success rate. For patients who are ready to undergo embryo transfer, the first step is to fully communicate with the doctor whether the endometrium is OK. If it is OK, prepare to schedule the transfer of embryos. Cooperate fully with the transfer doctor during the transfer process in order to complete the process successfully. Physical condition and status Heavy psychological stress can affect the endocrine level and therefore the success rate of IVF. High psychological stress often makes women nervous and causes disorders in the contraction of uterine muscles, resulting in failure of embryo transfer due to failure of embryo implantation. In addition to the above factors, one of the important reasons closely related to the outcome is age! As the ovaries gradually go into decline with age, the quality of eggs will get worse and the success rate of IVF pregnancy will drop significantly due to aging of egg cells and significantly higher chance of chromosomal aberrations. At the same time, as age increases and physical quality decreases, pregnancy will place a great burden on the heart, kidneys and liver, increasing complications during pregnancy and delivery and decreasing the rate of live births in advanced maternal age. Men likewise have poorer sperm quality with age, so. When you decide to have a child, prepare before it’s too late.