Ideally, medicine should deal with the childlessness of each infertile couple in two subsequent steps. First, all factors interfering with natural conception should be identified (see Chap. 20). Secondly, the targeted treatment of each factor contributing to the infertility should be identified and initiated. Unfortunately, neither in gynecology nor in andrology can many of the identified causes of infertility be overcome by a targeted treatment, so that instead a number of therapeutic strategies have been developed to deal with childlessness exclusively as a symptom without removing the cause of infertility itself. Most of these strategies can be summarized by the term “assisted reproduction”. The major disadvantage of any form of assisted reproduction is its short-term efficacy, because the therapeutic effect of assisted reproduction is active only during the treatment cycle itself. If this treatment cycle proves to be unsuccessful or if infertility recurs after delivery of a healthy baby, the entire treatment must be repeated.