[1] Copenhagen Univ Hosp North Zealand, Dept Paediat, Hillerod, Denmark
[2] Copenhagen Univ Hosp, Rigshosp, Juliane Marie Ctr, Dept Neonatol, Copenhagen, Denmark
[3] Univ Copenhagen, Dept Clin Med, Copenhagen, Denmark
[4] Copenhagen Univ Hosp North Zealand, Dept Cardiol, Hillerod, Denmark
[5] Univ Copenhagen, Dept Publ Hlth, Copenhagen, Denmark
[6] Copenhagen Univ Hosp North Zealand, Dept Obstet & Gynaecol, Hillerod, Denmark
[7] Prehosp Ctr, Naestved, Denmark
[8] Nordsjaellands Hosp, Dept Paediat, Dyrehavevej 29, DK-3400 Hillerod, Denmark