1. Department of Obstetrics and Gynecology, Pusan National University School of Medicine, Busan, Republic of Korea
2. Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea
3. Department of Obstetrics and Gynecology, Kyung Hee University Medical Center, Seoul, Republic of Korea
4. College of Medicine, University of Ulsan, Ulsan University Hospital, Ulsan, Republic of Korea
5. Department of Obstetrics and Gynecology, Kosin University Gospel Hospital, Kosin University College of Medicine, Busan, Republic of Korea
6. Department of Obstetrics and Gynecology, Busan Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea
7. Department of Obstetrics and Gynecology, Pusan National University Yangsan Hospital, Gyeongsangnam-do, Republic of Korea.