1. Department of Obstetrics and Gynecology, Duke University School of Medicine, Durham, NC, USA
2. Department of Obstetrics & Gynecology, Duke University, Durham, NC, USA
3. Department of Obstetrics & Gynecology, University of Mississippi, Jackson, MS, USA
4. Department of Obstetrics & Gynecology, Brigham and Women’s Hospital, Boston, MA, USA