What can be frozen during cryopreservation?

Cryopreservation options

There are various options for cryopreservation. Sperm cells, unfertilised eggs(social freezing), fertilised eggs, testicular tissue and ovarian tissue can be frozen. The possibilities of cryopreservation continue to develop due to modern techniques. In the following, we would like to show you the individual possibilities:

1. sperm cells

This cryopreservation option is very often used. If you decide to donate sperm from a third party (heterologous sperm donation), you will also receive frozen sperm from the donor. This type of "fertility reserve" is used by men, for example, when there is a high reduction in sperm count. Several sperm samples are frozen "in reserve" so that they can be used at a later date.

It can also happen that it is not possible for the man to give the sperm sample at short notice during fertility treatment. This may be for professional reasons, for example.

2. unfertilised eggs (social freezing)

Freezing unfertilised eggs has become a "lifestyle option". The term "social freezing" is used in this context. American companies (Apple, Facebook, among others) offer to cover the costs of cryopreservation for their female employees. This procedure met with massive criticism and was discussed. In Germany, a representative survey was conducted by the "ZEIT" newspaper. It showed that one in five respondents could imagine using a social freezing service.

Young women whose life plans do not yet include a desire for children and who are advancing in age often resort to cryopreservation. Often it is not yet possible for the women to have a child for professional reasons or they lack a suitable partner.

For women who have been diagnosed with cancer and have to undergo chemotherapy or radiation, freezing the unfertilised eggs can be beneficial. This option has become a standard in everyday practice. Cancer patients have immature eggs removed and frozen before treatment begins. After the successful treatment of the disease, the desire to have a child can be taken up.

In summary, cryopreservation of unfertilised eggs is referred to as "fertility precaution" for young women and also as the "fertility reserve" for sick women.

3. fertilised eggs

Cryopreservation of fertilised eggs is the most commonly used option. In the course of artificial insemination, several of the woman's eggs are fertilised. Since, according to the Embryo Protection Act, a maximum of 3 embryos may be transferred into the uterus, fertilised eggs usually remain.

It is worth freezing the remaining eggs. This way, if treatment is unsuccessful, you can fall back on existing eggs and there is no need to carry out hormone stimulation and puncture again. This eliminates the risk of overstimulation. Therefore, cryopreservation in this combination is gentle for the woman. If the woman wants to have a child again, she can use the frozen eggs again.

4. testicular tissue

If there is no semen in the seminal fluid (e.g. blockage of the seminal duct), tissue can be obtained using the TESE method and frozen for a later date.

5. ovarian tissue

For young cancer patients, this option can be used to fulfil the desire to have children after successful treatment. A "re-transplantation" of the ovarian tissue takes place after the treatment of the disease. This can even lead to a successful pregnancy in a "natural way".