[1] UCL Inst Child Hlth, ECS Coordinating Ctr, London WC1N 1EH, England
[2] Univ Padua, I-35100 Padua, Italy
[3] Charite Virchow Klinikum, Berlin, Germany
[4] Royal Hosp Sick Children, Edinburgh EH9 1LF, Midlothian, Scotland
[5] Hosp Infantil La Paz, Madrid, Spain
[6] Hosp La Fe, E-46009 Valencia, Spain
[7] Univ Amsterdam, Acad Med Ctr, NL-1105 AZ Amsterdam, Netherlands
[8] Karolinska Univ Huspital, Huddinge, Sweden
[9] Karolinska Univ Huspital, Solna, Sweden
[10] Hosp St Pierre, Brussels, Belgium
[11] UCL St Luc, Brussels, Belgium
[12] Univ Genoa, Infect Dis Clin, Genoa, Italy
[13] Univ Genoa, Dept Internal Med, I-16126 Genoa, Italy
[14] IST, Ist Nazl Ric Canc, SS Infettivol, Genoa, Italy
[15] Univ Genoa, Dept Obstet & Gynecol, Neonatol Unit, Genoa, Italy
[16] Univ Autonoma Barcelona, Hosp Mar, E-08193 Barcelona, Spain
[17] Univ Copenhagen, Hvidovre Hosp, DK-2650 Hvidovre, Denmark
[18] Hosp Clin Barcelona, Barcelona, Spain
[19] Hosp St Joan de Deu, Barcelona, Spain
[20] Osped L Sacco, Milan, Italy
[21] Univ Milan, Dept Pediat, L Sacco Hosp, Milan, Italy
[22] IRCCS Burlo Garofolo, Trieste, Italy
[23] St Marys Hosp, London, England
[24] Chelsea & Westminster Hosp, London, England
[25] Univ Naples Federico II, Dept Pediat, Naples, Italy
[26] Univ Naples Federico II, Dept Obstet, Naples, Italy
[27] Univ Turin, Turin, Italy
[28] Natl Res Inst Mother & Child, Warsaw, Poland
[29] Med Univ Warsaw, Infect Dis Hosp, Warsaw, Poland