1. Department of Obstetrics and Gynecology, Women & Infants Hospital, Providence, Rhode Island
2. Department of Obstetrics and Gynecology, West Virginia University, Morgantown, West Virginia
3. Department of Gynecology and Obstetrics, Johns Hopkins University School of Medicine, Baltimore, Maryland
4. Department of Obstetrics and Gynecology, Alpert Medical School of Brown University, Providence, Rhode Island