[1] Tor Vergata Univ, Dept Surg Sci, Rome, Italy
[2] Policlin Casilino, Div Obstet & Gynecol, Rome, Italy
[3] Univ Hosp Careggi, Dept Obstet & Gynecol Biomed Expt & Clin Sci, Florence, Italy
[4] Policlin Tor Vergata, Dept Integrated Care Serv, Prehosp Unit, Rome, Italy
[5] Azienda Osped Univ Careggi, Dept Anesthesia & Intens Care, Unit Obstet & Gynecol Anesthesia, Florence, Italy
[6] Osped Maggiore Policlin, Fdn IRCCS Ca Granda, Dept Obstet & Gynecol, Dept Woman Child & Newborn,Unit Obstet, Milan, Italy
[7] Univ Milan, Dept Clin & Community Sci, Milan, Italy
[8] Univ Parma, Dept Med & Surg, Obstet & Gynecol Unit, Parma, Italy
[9] Univ Brescia, Dept Clin & Expt Sci, Brescia, Italy
[10] ASST Grande Osped Metropolitano Niguarda, Maternal Infant Dept SC, Obstet & Gynecol, Milan, Italy
[11] San Giovanni Calibita Fatebenefratelli Hosp, Dept Anesthesia & Resuscitat Obstet, Rome, Italy
[12] IRCCS Ist Giannina Gaslini, Obstet & Gynecol Unit, Genoa, Italy
[13] IRCCS Burlo Garofolo, Inst Maternal & Child Hlth, Unit Fetal Med & Prenatal Diag, Trieste, Italy
[14] Univ Trieste, Dept Med Surg & Hlth Sci, Trieste, Italy
[15] Marche Polytech Univ, Dept Obstet & Gynecol, Ancona, Italy
[16] Polytech Univ Marche, Salesi Hosp, Dept Clin Sci, Ancona, Italy
[17] Policlin Tor Vergata, Viale Oxford 81, I-00133 Rome, Italy