1. Department of Obstetrics and Gynecology, Soonchunhyang University College of Medicine, Bucheon, Korea.
2. Department of Preventive Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
3. School of Human & Environment, Eulji University, Seongnam, Korea.
4. Department of Urology, Soonchunhyang University College of Medicine, Bucheon, Korea.