The ABC of Cryopreservation
Cryopreservation is a process where embryos, sperms, gametes, tissues from ovaries or testicles are kept intact so that they can be used in the future. This preservation helps in huge cost savings and resources which increases efficiency and reduces discomfort and inconvenience to the couples.
This process is performed in two simple steps. Firstly, the female and male sample is collected in straw like tubes at zero degree Celsius temperature to avoid specimens from getting frozen. This preserved sample is called cryopreservant and in the second step, these specimens are thawed before they are used. There are multiple protocols for this process as they vary in terms of storage temperature, type of cryopreservant, the time required for freezing and thawing and the type of specimen.
Use of Cryopreservation
There has been a tremendous advancement in cryopresevation. We, at Joy IVF Clinic uses advanced technology and methods in this process. The process of gamete retrieval, embryo creation and keeping them safe for the subsequent cycles of IVF gives certain advantages in the whole treatment process:
It Enhances The Efficiency: In this process, it helps in preserving the extracted embryos, sperms or matured eggs without having hassles of extracting them again. It not only saves time, energy and money but it is also beneficial for the women from getting the physical discomfort multiple times as we don’t need to stimulate ovaries again and again. Earlier, oocyte retrieval was a mandatory process with every attempt of IVF but now with the latest technology, this process can be done just once and can be used many times easily.
Lower Risk of Hyper Stimulation Syndrome: If the ovaries are stimulated multiple times using medicines, it can be very dangerous for the women and can even result to death as a lot of strain is created on the ovaries if they are stimulated many times to produce the egg. This process of cryopreservation helps a lot in this regard as the extracted eggs can be used more than one time. Earlier in IVF, doctors used to implant more than one egg to increase the probability of success. But in cryopreservation, it is not required as doctors can implant two or maximum embryos in one attempt and can preserve it for the future use.
Preservation Of The Fertility: Cryopreservation helps in preserving the sample for the females with the history of early menopause and for the couple undergoing chemotherapy or radiotherapy that results in risk of losing fertility early. In such cases, doctors preserve the embryo or sperm for later use.
How it is done?
Cryopreservation helps in freezing human tissues so that they can ‘live’ long for future use. It is important that the cells should not get damage while preserving so that they can become active and used again after thawing process. There are various protocols that are used to preserve the human tissues in extremely low temperature.
Types of Cryopreservation
- Sperm Freezing
- Egg and Ovarian Tissue Freezing
- Embryo Freezing
How Does Cryopreservation Happen?
Freezing protocols play a phenomenal role in the cryopeservation. It is the method of freezing the tissues. This method depends upon the kind of tissues that we are preserving while selecting the protocol as every tissue has a different composition and therefore, slow or fast protocol would depend on the tissues.
In this process, temperature is reduced to cool down the cryoprotectants and reproductive tissues. In this process, Cryoprotectants is added and temperature is decreased with a rate of minus two degrees per minute until it reaches minus seven degree Celsius. As soon as this temperature is achieved, the acceleration rate is reduced to -0.3 degree Celsius until it reaches -30 degree Celsius. The rate is again increased until the temperature goes to -135 degree Celsius and then finally tissues are stored in liquid nitrogen at the temperature of -196 degree Celsius.
In this process, tissues are plugged directly in the liquid and the temperature is dropped to 1-196 Celsius immediately. To avoid crystallization of cells, very high concentration of cryopreservant is used. Thawing the cryopreseved tissues is complex and critical to bring them to room temperature without getting damaged. The straw like tubes containing cyropresevent tissues are preserved in special water baths until the temperature rises to the room temperature. The medium of cryopreservation is diluted to avoid any kind of toxic effect.