1. Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of North Carolina, Chapel Hill, North Carolina, USA.
2. Division of General Obstetrics and Gynecology, Department of Obstetrics and Gynecology, University of North Carolina, Chapel Hill, North Carolina, USA.
3. Division of Global Women's Health, Department of Obstetrics and Gynecology, University of North Carolina, Chapel Hill, North Carolina, USA.
4. Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Duke University, Durham, North Carolina, USA.