Cryopreservation and vitrification
What is cryopreservation?
Cryopreservation is a technique for freezing reproductive cells using special media for retention in liquid nitrogen at a temperature of -196 ° C. With this method it is possible to store reproductive cells for many (even dozens) of years.
Our clinic will preserve the reproductive cells in a unique modern cryobank.
What is vitrification?
Vitrification is a modern cryopreservation technique based on sudden cooling of reproductive cells to a temperature of -196 ° C in seconds. It uses a medium containing high doses of cryoprotectants, protecting cells against damage. With respect to the high success rate of this technique, as compared to slow freezing, our clinic performs only the vitrification technique.
What can be frozen?
Standard cryopreservation allows preservation of embryos and sperm specimens. Advanced ultra-fast freezing (vitrification) also allows preservation of eggs.
How is freezing performed?
Vitrification of embryos is also performed using modern technology in an enclosed system with an internal carrier and external container. Embryos are almost immediately frozen. In contrast to the slow freezing, this system allows an increase in the success rate of fertility treatment using frozen embryos almost to the level of success achieved with fresh embryos. Freezing of eggs is similar to embryo freezing with vitrification.
Our clinic REPROFIT International participated in the international pilot study of a completely new system for vitrification of eggs, and as the world's first it marked success in the form of the first child born using this technique.
Freezing of sperm is, compared to the above mentioned technique, a relatively simple process that consists of mixing the semen or processed sperm with a freezing medium at a specific ratio and then placing it in liquid nitrogen vapour.
Cryopreservation of embryos
Cryopreservation of embryos is widely used in couples undergoing artificial fertilization, i.e. when there are other quality embryos which are no longer suitable for current embryotransfer.
Cryopreservation of surplus quality embryos belongs to one of the basic methods of an effective embryology laboratory. Introduction of ultra-fast freezing (vitrification) has brought significant improvements in the survival of frozen and subsequently thawed embryos and a significant increase in the success rate of cryoembryotransfers.
Success of cryopreservation
In our clinic, we only vitrify quality embryos at the blastocyst stage (day 5 or 6 of cultivation), which guarantees up to 98% success of survival of such embryos. Whether or not the remaining embryos are suitable for freezing is decided by the head of our embryology laboratory after personal examination of their quality.
Advantages of cryopreservation
At the present time of greater emphasis being placed on reducing the number of embryos for embryotransfer, vitrification is an integral part of treatment and provides our patients with a better chance of success in a single stimulation. In the subsequent cryoembryotransfer it eliminates the risk of ovarian hyperstimulation, the necessity of general anaesthesia, and its cost efficiency is also an important aspect.
Cryopreservation of sperm
Cryopreservation of sperm is used when a couple wants to keep the sperm specimens for future planned conception.
Cryopreservation of oocytes (eggs)
Cryopreservation of oocytes (eggs) is, thanks to vitrification, a standard part of infertility treatment. According to international studies, vitrification of eggs does not affect the course of pregnancy and does not increase the risk of having a child with a congenital defect.
When is the oocyte vitrification method used?
- In the event of imminent failure of ovarian function, when it allows the patients to preserve their own eggs for future use.
- In case of an imminent loss of fertility due to cancer treatment. Vitrification of eggs offers women of childbearing age before treatment of cancer to maintain the hope of getting pregnant when their disease is under control.
- In case of unexpected absence of partner's sperm in IVF treatment cycle. If, on the day of collection of eggs from a stimulated patient, it is not possible to obtain any sperm from the partner (for reasons of health, transport, work or temporary psychological state), the obtained eggs can be frozen.
- Also, if during a surgical sperm collection from the testicle (MESA-TESE) no sperm is found and the infertile couple does not want to opt for use of donor sperm, the collected oocytes can be frozen. Both partners thus gain time for consideration of possible solutions and the final decision on the type of treatment.
- Another option for the use of vitrification is the freezing of eggs in young women of childbearing age who do not currently have a partner and fear that by the time they have a partner their fertility might be impaired. Also women who do not plan on getting pregnant immediately and for reasons of study or employment procrastinate the term conception can have their eggs frozen.