1 Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Thomas Jefferson University Sidney Kimmel Medical College, 833 Chestnut St., Philadelphia, PA 19107.
2 Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Thomas Jefferson University Sidney Kimmel Medical College, 833 Chestnut St., Philadelphia, PA 19107. Electronic address: [email protected].