[1] McMaster Childrens Hosp, Div Neonatol, Dept Pediat, Hamilton, ON, Canada
[2] Ernst Moritz Arndt Univ Greifswald, Inst Community Med, Greifswald, Germany
[3] Ernst Moritz Arndt Univ Greifswald, Klin & Poliklin Kinder & Jugendmed, Greifswald, Germany
[4] Klin Kinder & Jugendmed, Dortmund, Germany
[5] Kinderkrankenhaus Bult, Hannover, Germany
[6] Univ Klin Kinderheilkunde, Bern, Switzerland
[7] Univ Kinderklin, Cologne, Germany