Freezing/ Vitrification
Cryopreservation/Freezing :
It is a method where sperm or oocytes or embryos are frozen at extremely low temperature (as low as -196 degree celsius), where the biological activity of the cell is completely halted. The commonly used medium for freezing is liquid nitrogen.
Egg freezing – Eggs retreived in the IVF cycle can be frozen either by vitrification or slow freezing method. Off late, vitrification method (rapid freezing) is the most commony used.
The intention of the procedure is that the woman may choose to have the eggs thawed, fertilized, and transferred to the uterus as embryos to facilitate a pregnancy in the future.
The pregnancy potential of cryopreserved oocytes is comparable to that of fresh oocytes or frozen embryos. Cryopreservation of oocytes would importantly contribute to oocyte donation and preservation of fertility for cancer patients.
Indications for Egg freezing :
- Conditions that might affect future fertility – Autoimmune disease like SLE, sickle cell anemia.
- Patients in need for cancer treatment – Radiotherapy or chemotherapy might harm your fertility
- Patients undergoing an IVF cycle
Semen cryopreservation – it is commonly called sperm banking or sperm freezing). It is a procedure to preserve sperm cells. Semen can be used successfully indefinitely after cryopreservation. It can be used for sperm donation where the recipient wants the treatment in a different time or place, or as a means of preserving fertility for men
undergoing vasectomy or treatments that may compromise their fertility, such as chemotherapy, radiation therapy or surgery.
Embryo Freezing :
In a typical IVF or ICSI treatment cycle, the woman’s ovaries are stimulated to produce many eggs. Following fertilisation and embryo culture, the best embryos are selected for embryo transfer. For about 50% of couples, there will also be good embryos, which are surplus to those required for embryo transfer. These embryos can be frozen at this point for future use. The main benefit of embryo freezing is the option to have frozen embryos thawed and transferred to the woman’s uterus in the future without having to undergo stimulation of the ovaries or egg retrieval.