1. Clinic for Neonatology , Muenchen Klinik Harlaching , Munich , Germany
2. University Hospital Freiburg , Division of Neonatology and Pediatric Intensiv Care Medicine, Department of General Pediatrics, Medical Center, University of Freiburg , Freiburg im Breisgau , Germany
3. Department of Obstetrics and Gynecology , University Hospital Freiburg , Freiburg im Breisgau , Germany
4. Institute of Medical Biometry and Statistics , University Hospital Freiburg , Freiburg im Breisgau , Germany