The process of embryo freezing on the twelfth day of IVF
IVF refers to the freezing of embryos after the fertilized eggs are cultured in vitro to a certain stage of development, and then thawing and resuscitation are carried out when necessary to help infertile couples successfully conceive and give birth. Embryo freezing is one of the important links of IVF technology, and embryo freezing is generally carried out at the twelfth day of embryo development. This process will be described in detail next.
Embryonic development
Before embryo freezing, it is necessary to understand the development process of the embryo. The fertilized egg is cultured in an in vitro incubation incubator. After different stages of development, it usually reaches the eight cell stage on the third day, and then develops into a blastocyst on the fifth to sixth days. When the embryo develops to the twelfth day, the embryo is usually frozen.
When the embryo develops to the twelfth day, it means that its cell division has been further carried out, and the internal structure of the embryo has also begun to form. At this time, the cells in the center of the embryo will form the embryo bud or embryo kernel, while the cells in the periphery will form the trophoblast. Embryos at this stage of development have high viability and implantation success rate, so they are suitable for cryopreservation.
Embryo freezing process
Embryo freezing is to preserve embryos at extremely low temperature to prevent embryo development and maintain the integrity and viability of its cells. Before freezing, doctors will evaluate the quality and development of embryos, and only select embryos with good development potential for freezing to improve the survival rate.
First, the doctor will take the blastocyst out of the incubator, and then slowly cool it to a very low temperature through special freezing liquid. The embryos are kept in the freezing solution for a period of time to gradually adapt to the low temperature environment, and finally they are placed in the liquid nitrogen tank for cryopreservation.
In the process of embryo freezing, the freezing speed and the composition of the freezing solution need to be strictly controlled to ensure that no cell damage and other irreversible damage will occur to the embryo during freezing and thawing. The freezing liquid is usually rich in protective substances, such as glycerol or diethylene glycol, which can protect embryonic cells from freezing damage caused by freezing at low temperatures.
Embryo thawing and transfer
When frozen embryos need to be used, doctors will take them out of the liquid nitrogen tank, thaw them quickly, and transfer them into the incubator. The thawing process requires strict control of temperature and time to avoid secondary damage to embryos.
The thawed embryos will be further cultured in the incubator to adapt to the internal environment. Generally speaking, after thawing, the embryo will rest for several hours to a day, and then it will be implanted into the mother's uterus through assisted reproductive technology. Women need proper rest after transplantation to improve the success rate of implantation.
Summary
The process of embryo freezing on the twelfth day of IVF is based on the specific time node of embryonic development. The embryonic development process usually reaches a high degree of development on the twelfth day, which is suitable for cryopreservation. The process of embryo freezing involves cooling, residence time and the selection of freezing liquid, which requires strict control of conditions to maintain the cell integrity and viability of the embryo. The thawed embryos will be transferred to the mother after further culture to achieve the successful pregnancy and delivery of IVF.
