Oocyte freezing is a process to preserve the mature oocytes of a woman wherein her reproductive potential is preserved. This is especially useful for women who want to delay their pregnancy.
Who are ideal candidates for oocyte preservation?
- would like to delay their pregnancy
- are about to undergo chemotherapy/ radiotherapy for cancer
- have a high likelihood for premature ovarian failure
- object to storing of frozen embryos due to religious concerns
Oocyte freezing process :
The oocytes are initially dehydrated.A cryoprotective solution is used to replace the water within the cell and inhibit the formation of ice crystals.
These oocytes are later loaded into straws and placed inside a liquid nitrogen canister for storage.
Fertilization of frozen eggs:
The frozen eggs are placed in warming solution and assessed. The eggs that have survived this thawing process are fertilized using ICSI or IMSI.
The ideal time to freeze the eggs?
There is no such ideal time. Any woman who is going to delay her pregnancy and is around 35 years of age is an ideal candidate for egg freezing.
How long can the eggs remain frozen?
There is no scientific evidence to show that frozen eggs decrease in quality over time. This means that embryos can be frozen for however long necessary.
Is egg freezing safe?
The largest published study of over 900 babies from frozen eggs showed no increased rate of birth defects when compared to the general population. Additionally, results from one study showed no increased rates of chromosomal defects between embryos derived from frozen eggs compared to embryos derived from fresh eggs. In 2014 a new study showed that pregnancy complications were not increased after egg freezing.
Success rates of oocyte freezing:
The age of the woman is the most important factor in determining success of fertilization and implantation.The next important factor is the experience of the Andrologist/ Embryologist. We are successfully able to retrieve 96% of frozen oocytes in our labs.