1. Children’s University Hospital Bonn, Department of Paediatric Endocrinology and Diabetology, Bonn, Germany
2. Children’s University Hospital Bonn, Department of Neonatology, Bonn, Germany
3. University Hospital Bonn, Institute of Medical Biometry, Informatics and Epidemiology (IMBIE),, Bonn, Germany
4. Centre of Child and Adolescent Medicine, Justus Liebig University Giessen, Division of Paediatric Endocrinology and Diabetology, Steroid Research and Mass Spectrometry Unit, Giessen, Germany
5. University Hospital Bonn, Institute of Clinical Chemistry and Clinical Pharmacology, Bonn, Germany
6. Children’s University Hospital Erlangen, Erlangen, Germany