1. Department of Obstetrics and Gynecology; Healthcare System Gangnam Center; Seoul National University Hospital; Seoul Korea
2. The Institute of Reproductive Medicine and Population; Medical Research Center; Seoul National University College of Medicine; Seoul Korea
3. Department of Internal Medicine; Healthcare System Gangnam Center; Seoul National University Hospital; Seoul Korea
4. Division of Gastroenterology and Hepatology; Stanford University School of Medicine; Stanford CA USA
5. Department of Radiology; Healthcare System Gangnam Center; Seoul National University Hospital; Seoul Korea
6. Department of Obstetrics and Gynecology; Seoul Municipal Boramae Hospital; Seoul Korea
7. Department of Obstetrics and Gynecology; Seoul National University College of Medicine; Seoul Korea