Setting
Data were gathered from the National Birth Registry of Austria between 2008 and 2017 after approval (EK Nr: 1576/2018) by the ethics committee of the Medical University of Vienna, Austria (Chairperson Dr. Juergen Zezula) on 8 August 2018, and reported according to the STROBE statement.15 The registry is operated and maintained by the Institute of Clinical Epidemiology of the Tirol Kliniken, collecting birth records of all 75 hospitals in Austria providing inpatient obstetric care, and thereby representing 99% of annual deliveries.