1. Department of Obstetrics, Gynecology and Pediatrics, Institute of Obstetrics and Gynecology, University of Udine, Udine, Italy;
2. Department of Obstetrics, Gynecology and Pediatrics, Institute of Obstetrics and Gynecology, University of Modena, Modena, Italy;
3. Department of Obstetrics, Gynecology and Pediatrics, Institute of Obstetrics and Gynecology, University of Pisa, Pisa, Italy