1. Department of Obstetrics and Gynecology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
2. Department of Obstetrics and Gynecology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan
3. Department of Obstetrics and Gynecology, Cathay General Hospital, Taipei, Taiwan
4. School of Medicine, National Tsing Hua University, Hsinchu, Taiwan