Affiliation: | 1. Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Tennessee Health Sciences Center, Memphis, TN;2. Maternal and Child Health Research Program, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA;3. Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA |