Cryopreservation refers to the process of preservation of oocytes, blastocysts, sperms and embryos in frozen state to make them available in future. Patients with hyperstimulation syndrome, excess oocytes or embryos, etc find this technique very useful to get their oocytes, sperms, embryos preserved by freezing and later retrieved in the hour of need. Males with anticipated collection problem can use this to pool their sample to be used later.

Cryopreservation is helpful for the patients with any one or more of the following conditions-

1.       Cycle cancellation leading to the danger of ovarian hyperstimulation

2.       Bad health conditions post oocyte aspiration

3.       Donor oocyte arrangements

4.       High progesterone level at the time of HCG injection

5.       Unfavorable implantation site

Although this sounds simple but is a very complicated procedure requiring sophisticated, advance and costly equipments, liquid nitrogen jars and other computerized machinery. First of all the collected oocytes, embryos and sperms that needs to be preserved are exposed to cryoprotective agents which dehydrate them. Then the resultants are put into the straws specially meant for the purpose in ehich they are allowed to be cooled slowly upto the temperature as low as -196 degree celcius. Straws are preserved into liquid nitrogen which allows them to be safe for eternity. Ideally embryos, sperms or oocytes should be freezed in the pre-nuclear stage.

Cryopreservation also claims great precaution so that cell’s structural integrity is not disturbed. Much of the efforts of cryopreservation is dedicated to keep the damage due to intra-cellular ice formation minimum. This is done by proper dehydration of the cells before freezing otherwise intra cellular crystals may be dangerous to the cells.

Dr Akash Sharma, the senior embryologist at Adam and Eve test tube bay and research centre is an expert of cryopreservation.