Applications
With this modern technique, many things are made possible and it is indeed a very useful technique. Here, we shall present to you two more frequently used application:
Semen [Sperm] & Embryo Cryopreservation:
Some people donate their sperms or some may have Assisted Reproductive Technology [ART]. How does cryopreservation actually play a part?
Well, sperms are living cells, so if we do not want to use them immediately, we need to find ways to preserve them. And cryopreservation is the solution. The donated sperms will be presevered using this technique and when they are needed, they will be thaw and are ready to use! The sperms are usually frozen for a period of one year; at this time, future arrangements are discussed. It is generally believed that sperm that have been through the freeze-thaw process are no more likely to result in birth defects than freshly ejaculated sperm.
What about ART? What has cryopreservation has to do with it?
As part of the usual process of in vitro fertilization [IVF, a method of ART], multiple eggs may be stimulated to grow, be recovered from the ovary and become fertilized. This may result in additional embryos in excess of the number that a couple would desire to have transferred back to the uterus at one time.
If the additional embryos are of sufficiently good quality to undergo the process of cryopreservation, this can be performed in order to provide another opportunity for embryo transfer. That is, if the IVF fresh embryo transfer does not result in pregnancy, the frozen embryos can be subsequently thawed and transferred to the uterus in either a natural menstrual cycle or a hormonally-controlled cycle. Alternatively, if the IVF cycle is successful, the embryos can be stored for several years should the couple decide to attempt to have more children. To achieve pregnancies after as long as five years of storage is possible. Success rates [pregnancies per embryo transfer procedure] are almost identical to those seen with fresh embryo transfers.
Worldwide, 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.
Endangered Species:
There is an urgent need to protect and conserve endangered wildlife in the world. The traditional means of doing this is to regulate human use of specific species or nature areas by legislation. However, the changes in environment and other circumstances have driven us into a situation where it is impossible to stop destruction of many species without special conservation programs. These programs have traditionally included breeding animals in captive surroundings, which again often is very difficult and limits the number of individuals thus restricting the genetic basis. A decrease in the genetic variation in a population results finally in failures in reproduction and total vitality.
The modern techniques [cryopreservation]make it possible to preserve large gene materials by freezing sperm or gametes [eggs]. Sperm freezing, artificial insemination and embryo transfer are routine methods in several domestic species and applications of these techniques may also be used in wild species.
So if the specific species happen to be extinct in the future,
we can thaw the frozen sperms and gametes and fertilize them under artificial
conditions [we believe that by then, technology would have advanced so much
that such artificial conditions will be possible]. This way, we can "revive"
the supposedly extinct species.
