1. Department of Obstetrics and Gynecology S Chiara Hospital Trento Italy
2. Department of Obstetrics and Gynecology Maggiore della Carità Hospital Università del Piemonte Orientale Novara Italy
3. Department of Obstetrics and Gynecology IRCCS Policlinico San Matteo Hospital and University of Pavia Pavia Italy
4. Department of Clinical Epidemiology Provincial Health Services (APSS) Trento Italy