1. Division of Gynecology and Obstetrics, Department of Surgical Sciences, University of Cagliari, 09124 Cagliari, Italy
2. Unit of Obstetrics and Gynecology, Santo Spirito Hospital, 65129 Pescara, Italy
3. Department of Obstetrics and Gynecology, SS. Annunziata Hospital, G. D’Annunzio University of Chieti-Pescara, 66100 Chieti, Italy
4. El.En. Group, 50041 Calenzano, Italy