1. Department of Neonatology, Antwerp University Hospital, University of Antwerp and Study Centre for Perinatal Epidemiology, Flanders, Belgium
2. Pediatric University Hospital, University of Saarland, Homburg, Germany
3. Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
4. Unit of Epidemiology, Ospedale Pediatrico Bambino Gesù, Rome, Italy
5. National Perinatal Epidemiology Unit, Oxford, United Kingdom
6. Department for Mother's and Infant's Health, Hospital S. Giovanni Calibita–Fatebenefratelli, Rome, Italy
7. Department of Health Science, University of Leicester, Neonatal Unit, Leicester Royal Infirmary, Leicester, United Kingdom
8. Health Care Inspectorate, Ministry of Health, Welfare and Sports, the Hague, Netherlands
9. Department of Pediatrics, Hvidovre University Hospital, Hvidore, Denmark
10. Department of Neonatology, University of Medical Sciences, Poznan, Poland
11. Department of Pediatrics, Hospital de São Sebastião, Sta Maria da Feira, Portugal
12. Institut National de la Santé et de la Recherche Médicale, UMR S149, Epidemiological Research Unit on Perinatal and Women's Health, and Université Pierre et Marie Curie-Paris 6, Paris, France