1 Department of Obstetrics and Gynecology, San Giovanni Calibita Fatebenefratelli Hospital Isola Tiberina, Rome, Italy.
2 Department of Obstetrics and Gynecology, Bolognini Hospital, Seriate, Italy.
3 Department of Obstetrics and Gynecology, San Giovanni Calibita Fatebenefratelli Hospital Isola Tiberina, Via di Ponte Quattro Capi, 39, Rome, Italy 00186. Electronic address: alessandrosvelato@virgilio.it.