Cryopreservation of Gametes

• Spermatozoa

It is a fact that cryopreservation of the male gametes is relatively easy and simple as compared to the female counterpart. The reason might be because of the huge quantity of sperms found in the semen. Even if the cryopreservation techniques are not that effective, you will still be left with good number of sperms.

There are some factors plays a major role in the effectiveness and success of cryopreservation technique of sperms.
• Semen quality – If you preserve the semen sample taken through normozoospermic method, then the survival is much higher, typically 25% as compared to a sample taken by oligoozoospermic method where the survival is 12%.

• Preparation of the semen – It is important to prepare the semen properly if the survival rate is required to be high. The method of semen washing also determines the survival rates. Typically normozoospermic semen samples survive 25% if they are taken just by normal preparation method. If the semen is taken by swim-up technique, then the survival rate is 36%. There is another method known as density gradient configuration that improves the survival rates significantly. Research indicates that there is an increase from 12% to 27% with swim-up technique and 23% with centrifugal technique.

Oocyte

It is certainly very difficult to cryopreserve Oocyte as compared to sperm. The eggs are usually very delicate and there is damage to the outer shell very easily irrespective of the techniques we use to preserve them. The latest cryopreservation protocols, however, have become very helpful in preserving the Oocyte in a better way. Although the survival rate for Oocyte is as high as 60%, but the rate of live births using the survived Oocyte is still much lower as compared to the fresh ones....