1. Department of Obstetrics and Gynecology, Azienda Ospedaliera Universitaria SS. Antonio e Biagio e Cesare Arrigo, 15121 Alessandria, Italy
2. Department of Gynecology and Obstetrics, University Hospital Maggiore Della Carità, School of Gynecology and Obstetrics, University of Eastern Piedmont, 28100 Novara, Italy
3. Department of Anatomic and Hystologic Pathology, Azienda Ospedaliera Universitaria SS. Antonio e Biagio e Cesare Arrigo, 15121 Alessandria, Italy
4. Department of Medical and Surgical Sciences, Institute of Obstetrics and Gynaecology, University of Foggia, 71122 Foggia, Italy