1. Department of Obstetrics and Gynecology, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
2. Department of Obstetrics and Gynecology, Luis Hora Memorial Regional Hospital, Bauko, Mountain Province, Philippines
3. Chang Gung University School of Medicine, Taoyuan, Taiwan
4. Department of Obstetrics and Gynecology, Mahkota Medical Centre, Melaka, Malaysia