Nowadays, more and more couples are opting for IVF technology, which is the process of removing eggs from a woman’s ovaries and having them combine with the man’s sperm to form an embryo, then transferring the embryo to the uterus so that it can be bedded in the mother’s uterus and become pregnant. The most important part of the IVF technique is the embryo transfer process, but not all women can be transferred during the egg retrieval cycle, and not all can be transferred in one successful transfer. It is at this point that the doctor will recommend freezing the embryos that have already been formed. So what are the benefits of performing embryo freezing? The existing technology of freezing and thawing embryos is very mature and stable, and the survival rate of embryo rethawing is close to 100%. Preserving the embryos in liquid nitrogen at minus 196°C gives the patient sufficient time to adjust the endometrial state and wait until the right time to “wake up” the embryos for the best results of the transfer. The state of the ovaries and endometrium after egg retrieval is different for each patient due to different drug sensitivity and different drug regimens. Some patients may cancel the transfer of a fresh cycle after egg retrieval due to factors such as endometrial and ovarian hyperstimulation, and hormone levels in the body that are not up to standard. At this time, it is necessary to freeze the embryos and, with the help of the doctor, to adjust all aspects of the indicators before the transfer of the frozen-thawed embryos. For most women, multiple embryos are formed in a single IVF cycle, and after the fresh cycle transfer, there will be good quality embryos left over, which can be frozen and preserved. If the fresh cycle fails, the frozen embryos can be thawed and recovered for transfer in a freeze-thaw cycle to increase the chance of conception. That is, one ovulation promotion and multiple transfers. In other words, the use of frozen embryo transfer can avoid another ovulation promotion and egg retrieval. It is worth noting that the endocrine environment and the receptivity of the endometrium in the body are also favorable for embryo implantation during a freeze-thaw cycle, and the chances of success are not lower than for a fresh cycle transfer. In addition to providing multiple transfer opportunities, freezing and thawing embryos can also help you to choose the number of embryos to be transferred, thus avoiding the risk of multiple pregnancies. Also, with the liberalization of second births in China, it provides room for many patients who have undergone IVF to have a fertility reserve.