Chih-Ting Chang1, Chin-Ru Ker1, Cheng-Yu Long2. 1. Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan. 2. Department of Obstetrics and Gynecology, Kaohsiung Municipal Siaogung Hospital, Kaohsiung, Taiwan. urolong@yahoo.com.tw.