1. Department of Medical Engineering, Yonsei University College of Medicine, Seoul 03722, Republic of Korea.
2. Institute of Women’s Life Medical Science, Department of Obstetrics and Gynecology, Yonsei University College of Medicine, Seoul 03722, Republic of Korea.
3. Department of Obstetrics and Gynecology, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Republic of Korea.
4. Department of Obstetrics and Gynecology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Republic of Korea.
5. Department of Obstetrics and Gynecology, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea.