Cryopreservation is the process of freezing biological material at extreme temperatures. It is to help cells to survive both cooling to extreme temperatures and thawing back to physiological conditions. So, based on this theory, one can be able to preserve sperm as well as oocyte or egg.
Sperm can be stored or say cryopreserved at very low temperature and can be used for future attempts of conception with using IUI or IVF. Semen cryopreservation is normally advised in following situation.
- The male partner is not be available for timed insemination.
- Men who experience difficulty in the process of semen collection
- For men whose reproductive health is susceptible with some medical treatments including cancer therapy.
Oocyte (Egg) Cryopreservation
For Egg freezing, it is require for patient to undergo ovarian stimulation and surgical procedures to acquire the oocytes. The oocytes are made chilled with effective methods including slow-rate cooling or ultra-rapid freezing (vitrification). Upon thawing, in vitro fertilization procedures are required to inseminate the eggs. Thereafter it is cultured for the resultant embryos. Chosen embryos may then be transferred into the patient’s uterus.
It is helpful for the women,
- who wish to defer family building into later years, at the time ovarian output may decline
- who wish to limit the number of embryos created by supported reproduction
- who faces treatment such as cancer therapy that may weaken ovarian function
Embryos can be cryopreserved and stored at very low temperatures to provide future opportunity for achieving conception. Embryo freezing is usually part of the in vitro fertilization and embryo transfer strategy when the number of high quality embryos exceeds the number required for immediate transfer into the uterus. Cryopreservation of human embryos has been shown to be a successful procedure and there are no reports of increased birth defects in pregnancies achieved through this process.