1. Paediatric Oncology Emma Children's Hospital, Amsterdam UMC Vrije Universiteit Amsterdam Amsterdam The Netherlands
2. Department of Obstetrics and Gynaecology Amsterdam UMC Vrije Universiteit Amsterdam Amsterdam The Netherlands
3. Princess Máxima Center for Pediatric Oncology Utrecht The Netherlands
4. Department of Obstetrics and Gynaecology Radboud University Medical Center Nijmegen The Netherlands
5. Willem‐Alexander Children's Hospital/Leiden University Medical Center Leiden The Netherlands
6. Dutch Childhood Oncology Group Utrecht The Netherlands
7. Department of Hematology Radboud University Nijmegen Medical Center Nijmegen The Netherlands
8. Beatrix Children's Hospital University Medical Center Groningen University of Groningen Groningen The Netherlands
9. Department of Paediatric Oncology and Heamatology Wilhelmina Children's Hospital University Medical Center Utrecht Utrecht The Netherlands
10. Department of Epidemiology Netherlands Cancer Institute Amsterdam The Netherlands