1. Perinatal Epidemiology Research Unit, Aarhus University Hospital, Aarhus, Denmark
2. Child and Adolescent Medicine, Aarhus University Hospital, Aarhus, Denmark
3. Department of Pediatrics, Aalborg University Hospital, Aalborg, Denmark
4. Department of Clinical Medicine, Aalborg University Hospital, Aalborg, Denmark
5. Department of Pediatrics, Randers Regional Hospital, Randers, Denmark
6. Department of Pediatrics, West Regional Hospital, Herning, Denmark
7. Department of Pediatrics, Viborg Regional Hospital, Viborg, Denmark
8. Department of Pediatrics, Vendsyssel Regional Hospital, Hjørring, Denmark