For couples with an unfulfilled desire to have children, cryopreservation is an important component on the way to the desired child. As part of cryopreservation, sperm, ova, embryos or testicular tissue are frozen and stored. This will allow them to be used later.
Cryopreservation is a complex but well-established method. About half the sperm survive freezing and thawing at a later date. That amount is usually sufficient to fertilize eggs in the course of an IVF or ICSI. The cryopreservation of embryos works largely without losses. Up to 95% of the frozen embryos can be retrieved viable from a frozen state.
In 2016, Chinese scientists found that the "baby-take-home-rate"after artificial insemination with frozen embryos is higher than with "fresh" ones.
The risk for the baby created from thawed body cells is no higher than for babies conceived by other means. Also the risk of a miscarriage remains the same.
During cryopreservation, we place the body cells in liquid nitrogen. They cool down to up to 196 degrees Celsius. Before freezing, we remove water from the cells, in order to avoid the formation of crystals, which would destroy the cells. This method is called vitrification ("glazing"). It has been used successfully for over ten years. Despite the low temperature, the vital functions of the cells are preserved.
Cryopreservation is mainly used in these two situations:
1. ) cryopreservation in the course of artificial insemination
As part of a fertility treatment, we can freeze sperm, eggs and supernumerary embryos.
Cryopreserved sperm can be used for IVF treatment or insemination. As a rule, sperm cells are less mobile after thawing than fresh ones. Therefore it depends on the individual spermiogram, whether the freezing makes sense. We clarify this in individual cases and discuss the details with you.
The pregnancy rate when using frozen eggs is slightly lower than with fresh ones. Nevertheless, it makes sense to freeze supernumerary oocytes. This "backup" is helpful in case of a new treatment cycle, because the removal of fresh oocytes (puncture) is not necessary. Also there is no need for a new hormonal stimulation, which might be a significant relief for the woman.
Often, several suitable embryos (fertilized eggs) are created in the course of artificial insemination. We put a maximum of two in the uterus. Upon request, we freeze the surplus embryos. The cryopreserved embryos, which survive freezing and thawing unscathed, will be transferred as needed at a later date. As a result, you no longer have to go through all the treatment steps of an IVF or ICSI. The burden on your body is lower. The pregnancy rate when using thawed embryos is only slightly lower than in embryos that are developed in vitro without cryopreservation.
2. ) cryopreservation in case of cancer or testicular disease
Freezing is suitable for:
Male patients who have to face a cell-damaging therapy, such aschemo- or radiotherapy. Since those treatments have an impact on fertility, we freeze the sperm cells in case there is the wish for a child.
Patients with testicular disease.
Men who have had a testicular biopsy can freeze the tissue samples which contain sperm cells.
Female patients who are facing chemo- or radiotherapy. We take eggs before starting treatment and freeze them.
"With the cryopreservation we have already supported many couples on their way to the desired child."