1. School of Nursing, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
2. Department of Obstetrics and Gynecology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
3. Department of Social Medicine and Center for Bioethics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
4. Department of Obstetrics and Gynecology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA