1. Department of Paediatrics and Adolescent Medicine, Lillebaelt Hospital, University Hospital of Southern Denmark, 6000 Kolding, Denmark
2. Population Health Research Institute, St George’s University of London, London SW17 0RE, UK
3. Department of Regional Health Research, University of Southern Denmark, 5230 Odense, Denmark
4. IMER Registry, Centre for Clinical and Epidemiological Research, University of Ferrara and Azienda Ospedaliero Universitario di Ferrara, 44121 Ferrara, Italy
5. Rare Diseases Research Unit, Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, 46020 Valencia, Spain
6. Unit of Epidemiology of Rare Diseases and Congenital Anomalies, Institute of Clinical Physiology, National Research Council, 56124 Pisa, Italy
7. THL Finnish Institute for Health and Welfare, Department of Knowledge Brokers, 00271 Helsinki, Finland
8. Karolinska Institutet, Department of Molecular Medicine and Surgery, 171 77 Stockholm, Sweden
9. Faculty of Life and Health Sciences, Ulster University, Belfast BT15 1AP, UK
10. Faculty of Medicine, Health & Life Sciences, Swansea University, Swansea SA2 8PP, UK
11. Malformation Monitoring Centre Saxony-Anhalt, Medical Faculty, Otto-von-Guericke-University Magdeburg, 39106 Magdeburg, Germany
12. Congenital Anomaly Register & Information Service for Wales (CARIS) Public Health Knowledge and Research, Public Health Wales, Swansea SA6 8DP, UK
13. Section of Epidemiology, Department of Public Health, University of Copenhagen, 1353 Copenhagen, Denmark