Chin-Jung Wang1, Justina Go2, Yu-Cheng Liu3. 1. Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital at Linkou, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan. Electronic address: wang2260@gmail.com. 2. Department of Obstetrics and Gynecology, Chinese General Hospital and Medical Center, Manila, Philippines. 3. Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital at Linkou, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan.