[1] Childrens Hosp Tuebingen, Pediat Nephrol, Hoppe Seyler Str 1, D-72076 Tubingen, Germany
[2] Univ Hosp Tuebingen, Dept Obstet, Tubingen, Germany
[3] Univ Childrens Hosp, Pediat Nephrol, Zurich, Switzerland
[4] Univ Freiburg, Cochrane Germany, Med Ctr, Freiburg, Germany
[5] Paris Descartes Univ, Cochrane France, Ctr Rech Epidemiol & Stat, Sorbonne Paris Cite CRESS,Inserm,UMR1153, Paris, France
[6] Univ Zurich Hosp, Dept Neonatol, Zurich, Switzerland
[7] Univ Zurich, Zurich, Switzerland