[1] INSERM, U149, Epidemiol Res Unit Perinatal & Womens Hlth, Paris, France
[2] TNO, Inst Prevent & Hlth, Div Child Hlth, Leiden, Netherlands
[3] Maternal & Child Hlth Inst Burlo Garofolo, Epidemiol Unit, Trieste, Italy
[4] Univ Copenhagen, Rigshosp 4031, Dept Obstet, DK-1168 Copenhagen, Denmark
[5] Ctr Hosp Luxembourg, Dept Neonatol, Luxembourg, Luxembourg
[6] Reg Agcy Hlth Tuscany, Florence, Italy