1. Karolinska Institutet , Department of Women’s and Children’s Health, Pediatric Endocrinology Unit , Stockholm , Sweden
2. Department of Pediatrics , Medical Faculty, University of Cologne, Pediatric Endocrinology Unit , Cologne , Germany
3. Department of Pediatrics , Medical Faculty, University of Lübeck, Pediatric Endocrinology Unit , Lübeck , Germany
4. NORDFERTIL Research Lab Stockholm, Childhood Cancer Research Unit, Department of Women’s and Children’s Health , Karolinska Institutet, Karolinska University Hospital , Solna , Sweden