[1] Tufts Univ, New England Med Ctr, Div Newborn Med, Dept Pediat, Boston, MA 02111 USA
[2] Hannover Med Sch, Dept Pediat Pulmonol & Neonatol, Perinatal ID Epidemiol Unit, D-3000 Hannover, Germany
[3] Hannover Med Sch, Dept Gynecol & Obstet, D-3000 Hannover, Germany
[4] Childrens Hosp, Dept Neurol, Neuroepidemiol Unit, Boston, MA 02115 USA
[5] Harvard Univ, Sch Med, Boston, MA USA
[6] INSERM, U676, Paris, France
[7] Univ Paris 07, Fac Med Denis Diderot, IFR02, Paris, France
[8] Univ Paris 07, Fac Med Denis Diderot, IFR25, Paris, France