[Cryopreservation of human spermatozoa or testicular tissue for fertility preservation].

Loss of reproductive capacity due to treatments for malignant or non-malignant diseases or even as a result of diseases themselves significantly impacts patients' quality of life. Cryopreservation of sperm from ejaculate is a well-established procedure for preserving the fertility of these patients and thus improving their quality of life in the long term. If cryopreservation of sperm from ejaculate is not possible, either because ejaculation cannot occur or no sperm can be found in the ejaculate, the preferred treatment option is (microsurgical) testicular sperm extraction (mTESE). Testicular sperm and ejaculated spermatozoa can be cryopreserved and later used for intracytoplasmic sperm injection (ICSI) treatment. The use of cryopreserved sperm for fertility treatment does not carry an increased risk of malformations in the offspring. If gonadotoxic therapy is necessary in pre- or early pubertal boys, the only option to preserve fertility in the long term is to cryopreserve spermatogonial stem cells from testicular tissue as part of the Androprotect© network. This is an experimental approach which has been available since 2012 across Germany and which is accompanied by intensive scientific work ( www.androprotect.de ).