1. Department of Obstetrics and Gynecology, Korea University College of Medicine, Seoul, Republic of Korea.
2. Olson Center for Women's Health, Department of Obstetrics and Gynecology, and Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska.
3. Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
4. School of Industrial Management Engineering, Korea University, Seoul, Republic of Korea.