Acknowledgments We are grateful to the participating children and their families, all maternity and neonatal units in France, and all national and regional collaborators who made EPIPAGE-2 possible. We also would like to thank the collaborators of the  EPIPAGE-2 Obstetric Writing Group :  Pierre-Yves Ancel, MD, PhD  ( Université Paris Cité, Epidemiology and Statistics Research Center/ CRESS, Inserm, INRAE ,  F-75004 Paris, France ,  Unité de Recherche Clinique e Centre d'Investigations Cliniques P1419 ,  Département Hospitalo-Universitaire Risks in Pregnancy, Cochin Hotel-Dieu Hospital ,  Assistance Publique-Hôpitaux de Paris, Paris F-75014, France );  Catherine Arnaud, MD, PhD  ( Research Unit on Perinatal Epidemiology, Childhood Disabilities and Adolescent Health, Inserm UMR 1027, Paul Sabatier University, Toulouse, France );  Chloé Arthuis, MD, PhD  ( Department of Gynecology and Obstetrics, CIC, University hospital of Nantes, Nantes, France );  Julie Blanc, MD, PhD  ( Université Paris Cité, Epidemiology and Statistics Research Center/CRESS, Inserm, INRAE, F-75004 Paris, France ,  Department of Obstetrics and Gynecology, Aix Marseille University, Marseille, France );  Pascal Boileau, MD, PhD  ( Department of Neonatal Pediatrics, Poissy Saint Germain Hospital, France ,  EA7285 Versailles Saint Quentin en Yvelines University, France );  Thierry Debillon, MD, PhD  ( Department of Neonatal Pediatrics, University Hospital, Grenoble, France );  Pierre Delorme, MD, PhD  ( Université Paris Cité, Epidemiology and Statistics Research Center/CRESS, Inserm, INRAE, F-75004 Paris, France ,  Department of Obstetrics and Gynecology, Trousseau Hospital, AP-HP, Paris, France );  Claude D'Ercole, MD  ( Department of Obstetrics and Gynecology, Nord Hospital, Assistance Publique des Hôpitaux de Marseille (AP-HM ),  Aix Marseille Université, AMU, Marseille, France );  Thomas Desplanches, RM, PhD  ( Université Paris Cité, Epidemiology and Statistics Research Center/CRESS, Inserm, INRAE, F-75004 Paris, France );  Caroline Diguisto, MD, PhD  ( Université Paris Cité, Epidemiology and Statistics Research Center/ CRESS, Inserm, INRAE ,  F-75004 Paris, France ,  Maternité Olympe de Gouges ,  University Francois Rabelais, Tours, France );  Laurence Foix-L'Hélias, MD, PhD  ( Université Paris Cité, Epidemiology and Statistics Research Center/ CRESS, Inserm, INRAE, F-75004 Paris, France ,  Department of Neonatal Pediatrics, Trousseau Hospital, AP-HP, Paris, France );  Géraldine Gascoin, MD, PhD  ( Department of Neonatal Medicine, University Hospital, Toulouse, France, Research Unit on Perinatal Epidemiology, Childhood Disabilities and Adolescent Health, Inserm UMR 1027, Paul Sabatier University, Toulouse, France );  Catherine Gire, MD  ( Department of Neonatology, North Hospital, Marseille, France );  François Goffinet, MD, PhD  ( Université Paris Cité, Epidemiology and Statistics Research Center/CRESS, Inserm, INRAE, F-75004 Paris, France ,  Department of Obstetrics and Gynecology, Cochin, Broca, Hôtel Dieu Hospital, AP-HP, Paris, France );  Isabelle Guellec, MD, PhD  ( Pediatric and Neonatal Intensive Care Unit, University Hospital, Nice, France, Université Paris Cité, Epidemiology and Statistics Research Center/CRESS, Inserm, INRAE ,  F-75004 Paris, France );  Gilles Kayem, MD, PhD  ( Université Paris Cité, Epidemiology and Statistics Research Center/CRESS, Inserm, INRAE ,  F-75004 Paris, France ,  Sorbonne Universités ,  UPMC Univ Paris 06, IFD, 4 Place Jussieu ,  75252 PARIS cedex 05, Paris, France ,  Department of Obstetrics and Gynecology, Trousseau Hospital, AP-HP , Paris, France );  Bruno Langer, MD  ( Department of Obstetrics and Gynecology, Hautepierre Hospital, Strasbourg, France );  Mathilde Letouzey, MD, PhD  ( Université Paris Cité, Epidemiology and Statistics Research Center/CRESS, Inserm, INRAE, F-75004 Paris, France ,  Department of Neonatal Pediatrics, Poissy Saint Germain Hospital, France );  Elsa Lorthe, RM, PhD  ( Université Paris Cité, Epidemiology and Statistics Research Center/ CRESS, Inserm , INRAE, F-75004 Paris, France); Emeline Maisonneuve, MD, MSc (Department of Obstetrics and Gynecology, Trousseau Hospital, APHP, Paris, France); Stéphane Marret, MD, PhD (Department of Neonatal Medicine, Rouen University Hospital and Région-Inserm (ERI 28), Normandy University, Rouen, France); Isabelle Monier, RM, PhD (Université Paris Cité, Epidemiology and Statistics Research Center/ CRESS, Inserm, INRAE, F-75004 Paris, France); Andrei Morgan, MD, PhD (Université Paris Cité, Epidemiology and Statistics Research Center/.