Affiliation: | 1. Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Thomas Jefferson University, Philadelphia, PA;2. Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Pennsylvania Hospital, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA;3. Department of Obstetrics and Gynecology, University of Bologna, Bologna, Italy;4. Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, AL |