1 Obstetrics and Gynecology Unit, Mother-Infant and Adult Department of Medical and Surgical Sciences, University of Modena and Reggio Emilia, Modena, Italy.
2 Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Thomas Jefferson University Hospital, Philadelphia, PA.
3 Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Thomas Jefferson University Hospital, Philadelphia, PA. Electronic address: vincenzo.berghella@jefferson.edu.