The process of egg freezing starts from
1. Hormones injection for ovarian stimulation. It is an abdominal subcutaneous injection. Patient will take the injection for 8-12 days, start from 2 nd or 3 rd day of period. In order to have the ovary to produce multiple eggs, instead of creating only a single egg for the ovulation in each cycle naturally.
2. Once the patient has enough matured eggs, doctor will proceed a transvaginal operation called ovum retrieval to collect eggs. It takes around 20-30 minutes under the anesthesia.
3. Embryologists will prepare the egg by disintegrating cumulus cells and separating the immature oocytes (GV: Germinal Vesicle, MI: Metaphase I). Then select only fully matured eggs or MII (Metaphase II) stage to be frozen.
4. After that, the selected eggs will be immersed in the special freezing liquid. This process is vitrification. By reducing water inside egg cells in order to protect the frozen eggs from being frosty.
5. The eggs will be stored in liquid nitrogen at -196 Degree Celsius. We can keep them for decades with the same condition as beginning.
As you can see, the ovarian stimulation in egg freezing program is similar to the process in IVF/ICSI program. But the retrieved eggs in egg freezing program will be immediately frozen without fertilization. Meanwhile, the eggs in IVF/ICSI program need to combine with sperm outside human body in order to have an embryo. Therefore, egg freezing is a solution for family planning. Moreover, it can maintain the quality of egg against deterioration by aging. Since the frozen eggs will be still as young and fresh as they are in the beginning. Ready for the future need.
Previously, “Slow Freezing” technology made a success of freezing more than 24years. For example, “The American couple gives birth from 24 year-frozen embryo.” news. Nowadays, the vitrification technique is more modern and productive. So, freezing fordecades can create a satisfactory result as well.
Reference:
https://www.theguardian.com/society/2020/feb/19/first-baby-born-through-new-egg-freezing-fertility-technique-ivf
https://hilight.kapook.com/view/165438
