1. CRESS, Obstetrical Perinatal and Paediatric Epidemiology Research Team, EPOPe, INSERM, INRA Universite de Paris Paris France
2. Centre for Maternal and Child Health Research School of Health Sciences City, University of London London UK
3. Perinatal Epidemiology and Reproductive Health Unit CR2, School of Public Health ULB Brussels Belgium
4. Institute for Quality Assurance and Transparency in Health Care Berlin Germany
5. Directorate for Social Statistics and Welfare Italian Statistical Institute (ISTAT) Rome Italy
6. Department of Obstetrics & Gynaecology Maastricht University Medical CentreMUMC+ Maastricht The Netherlands
7. Department of Obstetrics and Gynaecology Landspitali University Hospital Reykjavik Iceland
8. Department of Epidemiology and Biostatistics National Research Institute of Mother and Child Warsaw Poland
9. THL Finnish Institute for Health and Welfare Helsinki Finland
10. Karolinska Institute Stockholm Sweden