Iris de Nie

137 GENERAL DISCUSSION AND FUTURE PERSPECTIVES 9 in the cohort studies on the incidence of cancer in trans women. In addition, we were able to optimize our databases through collaborations with institutes such as the Nationwide Network and Registry of Histopathology and Cytopathology in the Netherlands (PALGA) and Statistics Netherlands (CBS) who provided us with reliable data on cancer diagnoses and mortality, and other departments such as the Reproductive Biology Laboratory who enabled the use of immunohistochemical markers to validate our findings regarding the most advanced germ cell types in testicular tissue. 137,138 Lastly, we experienced few missing data in the prospective cohort studies. However, there are also some limitations. First, we did not include control groups in the studies on semen quality. Therefore, we could only assess the influence of demographics, lifestyle and medical history within the study population, but we were not able to assess if these factors were different from the general population. By comparing our data with data on lifestyle in the Dutch general population of similar age from CBS, and data on semen parameters in the general population of unscreened men from the World Health Organization (WHO), we aimed to overcome this limitation. 10,74 Another possible solution would have been to include a cis male control group who pursued fertility preservation for nonmedical reasons. Secondly, for both the survey study on the importance of fertility and family building, as well as for the case series on restoration of spermatogenesis following GAHT, it would have been valuable to also have a data on the study parameters before and (in the first years) during GAHT. This would allow for a more longitudinal observation of changes over time. Furthermore, for the study on the incidence of prostate cancer in trans women, we lacked information about the clinical symptoms that led to the diagnosis and the response to treatment, since the majority were diagnosed and treated in other hospitals than our clinic. This information would have been helpful to enhance early detection of prostate cancer in trans women and to provide recommendations regarding treatment in this population. Lastly, a limitation of the study on testicular cancer incidence in trans women is that, despite the large cohort size, follow-up time was relatively short due to the fact that the majority of trans women decided to undergo bilateral orchiectomy directly after the required minimum of twelve months GAHT. FUTURE PERSPECTIVES Implications for clinical practice Andrological care is relatively new in the field of transgender medicine since, until 2014, strict transgender laws were in place which required a sterilization for legal gender recognition. Therefore, almost all trans women underwent gonadectomy, and reproductive wishes and the options for fertility preservation were hardly discussed. As a result, studies on family building, fertility (preservation) and the long term effects of GAHT on testicular tissue were scarce. Over the last couple of years the interest, and concomitant research output, in this field has increased substantially. Nowadays, there is a general consensus that it is essential to provide counseling about the effect of medical treatment on fertility and the currently available options for fertility preservation. Furthermore, the Ethics Committee