1. Department of Obstetrics and Gynecology, Women and Infant's Hospital, Brown University, Providence, Rhode Island; Department of Obstetrics and Gynecology, University of Vermont College of Medicine, 89 Beaumont Ave., Burlington, VT 05403
2. Department of Obstetrics and Gynecology, University of Vermont College of Medicine, Burlington, Vermont; Department of Obstetrics and Gynecology, Women and Infant's Hospital, Brown University, Providence, Rhode Island