1. Department of Obstetrics and Gynecology; University of Cagliari, Policlinico Universitario Duilio Casula; Monserrato Cagliari Italy
2. Department of Obstetrics and Gynecology; Hospital Universitario Virgen de la Arrixaca; Murcia Spain
3. Department of Obstetrics and Gynecology; Clínica Universidad de Navarra, School of Medicine, University of Navarra; Pamplona Spain