1. Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
2. Department of Obstetrics and Gynecology, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC
3. School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC
4. Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC