Affiliation: | 1. Department of Obstetrics and Gynecology, Tufts Medical Center, Boston, Massachusetts USA;2. Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts USA;3. Harvard University, Cambridge, Massachusetts USA;4. Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, Massachusetts USA;5. Department of Surgery Children's Hospital, Boston, Massachusetts USA |