1. Department of Obstetrics and Gynaecology, Ospedale Degli Infermi, Biella University of Turin Turin Italy
2. Department of Obstetrics and Gynaecology 2U Sant'Anna Hospital, University of Turin Turin Italy
3. Department of Obstetrics and Gynaecology Sant'Anna Hospital Turin Italy
4. Department of Foetal and Maternal Pathology Sant'Anna Hospital Turin Italy