1. 1NORDFERTIL Research Lab Stockholm, Pediatric Endocrinology Unit, Department of Women’s and Children’s Health, Karolinska Institutet and University Hospital, Stockholm, Sweden
2. 2Division of Haematology-Oncology and Stem Cell Transplantation, Children’s Hospital, University of Helsinki, Helsinki University Central Hospital, Helsinki, Finland
3. 3MRC Centre for Reproductive Health, The Queen’s Medical Research Institute, The University of Edinburgh, Edinburgh, UK
4. 4Edinburgh Royal Hospital for Sick Children, Edinburgh, UK