1. Clinical Epidemiology Division, Department of Medicine Solna Karolinska Institutet Stockholm Sweden
2. Department of Clinical Science and Education Södersjukhuset Karolinska Institutet Stockholm Sweden
3. Sachs' Children and Youth Hospital, Södersjukhuset Stockholm Sweden
4. Centre for Reproductive Epidemiology Lund University Lund Sweden
5. Unit of Pediatrics, Institute of Clinical Sciences University of Umeå Umeå Sweden
6. Department of Pediatrics, Institute of Clinical Sciences The Queen Silvia Children's Hospital, University of Gothenburg Gothenburg Sweden
7. Angered Hospital Angered Sweden
8. Department of Clinical Sciences, Lund, Pediatrics Lund University Lund Sweden
9. Folkhälsan Research Center Helsinki Finland
10. Children's Hospital Clinicum, University of Helsinki Helsinki Finland
11. Karolinska University Hospital Stockholm Sweden
12. Department of Women's and Children's Health Karolinska institutet Stockholm Sweden
13. Department of Women's and Children's Health Uppsala University Uppsala Sweden