1. Department of Family & Preventive Medicine, Emory University School of Medicine, Atlanta, GA, USA
2. Department of Gynecology–Obstetrics, Emory University School of Medicine, Atlanta, GA, USA
3. Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
4. Department Maternal-Fetal Medicine, Perinatal Research Center, Nashville, TN, USA
5. Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, TX, USA