1. Department of Women's and Children's Health Uppsala University Uppsala Sweden
2. Department of Pediatrics Institute of Clinical Sciences Umeå University Umeå Sweden
3. Department of Pediatrics Karolinska University Hospital Huddinge Stockholm Sweden
4. Department of Pediatrics Lund University Lund Sweden
5. Department Ophthalmology Uppsala University Uppsala Sweden
6. Department of Obstetrics and Gynecology Lund University Lund Sweden
7. Department of Pediatrics Örebro University Örebro Sweden
8. Department of Pediatrics Linköping University Linköping Sweden
9. Department of Pediatrics Sahlgrenska University Hospital Göteborg Sweden
10. Department of Obstetrics and Gynecology Karolinska University Hospital Huddinge Stockholm Sweden
11. Centre for Reproductive Epidemiology Lund University Lund Sweden