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. In sperm, about half survive freezing and later thawing. The remaining amount is usually sufficient to fertilize eggs in the course of an IVF or ICSI. The cryopreservation of embryos works largely lossless. Up to 95% of the frozen embryos can be thawed vital again.
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 of developing baby from thawed body cells is no greater than that of babies conceived in any other way. 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. Thereby we avoid the crystal formation, 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 excess oocytes. This "backup" is helpful if a new treatment cycle becomes necessary. If frozen eggs are present, the removal of fresh oocytes (puncture) can be dispensed with. This represents a significant relief for the woman. This can be dispensed with a renewed hormonal stimulation.
Frequently, in the course of artificial insemination, several suitable embryos (fertilized ova) are formed. 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 for cancer or testicular disease
Freezing is suitable for:
Male patients on whom a cell-damaging therapy is pending. For example, if chemotherapy or radiotherapy is planned. Such treatments reduce fertility. If there is still a wish for a child, we freeze the sperm cells before starting treatment.
Patients with testicular disease.
Men who have had a testicular biopsy can freeze the tissue samples containing seeds.
Patients who are facing chemotherapy or radiotherapy. We take eggs before starting treatment and freeze them.
"With the cryopreservation we have already supported many pairs of children on the way to the desired child."