1. INSERM, Obstetrical, Perinatal and Pediatric Epidemiology Research Team, Center for Epidemiology and Biostatistics (U1153), Paris-Descartes University, Paris, France,
2. Service de Médecine et Réanimation néonatales de Port-Royal, Hôpitaux Universitaires Paris Centre Site Cochin, Université Paris V René Descartes and Assistance Publique Hôpitaux de Paris, Paris, France,
3. Department of Neonatology, Antwerp University Hospital, University of Antwerp and Study Centre for Perinatal Epidemiology Flanders, Belgium, and
4. Research Unit of Perinatal Epidemiology, Bambino Gesù Children’s Hospital, Viale Ferdinando Baldelli 41, Roma, Italy