1. Division of Pediatrics, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
2. Department of Neonatal Medicine, Karolinska University Hospital, Stockholm, Sweden
3. Department of Clinical Science/Pediatrics, Umeå University, Umeå, Sweden
4. Swedish Neonatal Quality Registry, Umeå, Sweden
5. Division of Reproductive Health, Department of Women’s and Children’s Health, Karolinska Institutet, Sweden
6. The Swedish National Patient Insurance, Stockholm, Sweden