1. Division of Obstetrics and Gynecology, Department of Experimental and Clinical Medicine, University of Pisa, 56126 Pisa, Italy
2. Department of Obstetrics and Gynecology, Ankara University School of Medicine, 06100 Ankara, Turkey
3. SOD Clinical Trial Statistical Support, Azienda Ospedaliero Universitaria Pisana, 56126 Pisa, Italy
4. Department of Provincial Health Services, Local Health of Trento, 38123 Trento, Italy
5. Department of Obstetrics and Gynecology, Santorso Hospital, 36014 Vicenza, Italy
6. Department of Obstetrics and Gynecology, Centre Hospitalier de Troyes, 10003 Troyes, France