Embryo freezing is the only proven method of preserving fertility. The technology of freezing embryos is to store the embryos obtained through test tube cultivation technology in a liquid nitrogen environment at minus 196°C for long-term storage. If treatment fails this cycle , these embryos can be thawed and transferred in a later natural cycle.

Put the embryos and freezing liquid into the freezing tube , and through slow (2-3 day embryos) and fast (5-6 day blastocyst ) cooling methods, the embryos can be still and can be stored at 196 degrees. A method of preservation in liquid nitrogen. If there are remaining embryos with better quality, they can be frozen and stored, and then implanted into the uterine cavity after thawing in the natural cycle or artificial cycle , which will increase the chance of conception.