1. University of Freiburg, Faculty of Medicine, Germany, Center for Pediatrics, Department of Neonatology, Medical Center, Freiburg, Germany
2. University Medical Center of Johannes Gutenberg, University Mainz, Division of Neonatology, Department of Pediatrics, Mainz, Germany
3. Inselspital, Bern University Hospital, Division of Neonatology, Department of Pediatrics, Bern, Switzerland