1. 1Department of Endocrinology and Center of Expertise on Gender Dysphoria, VU University Medical Center, Amsterdam, the Netherlands
2. 2Department of Clinical Epidemiology, Leiden University and Medical Center, Leiden, the Netherlands
3. 3Department of Endocrinology, Oslo University Hospital, Oslo, Norway
4. 4Sexual Medicine and Andrology Unit, Department of Experimental, Clinical and Biomedical Sciences, University of Florence, Florence, Italy
5. 5Department of Endocrinology & Center for Sexuology and Gender, Ghent University Hospital, Ghent, Belgium