Cheng-Yu Long1, Gin-Den Chen2, Rebecca G Rogers3. 1. Department of Obstetrics and Gynecology, Kaohsiung Municipal Siaogung Hospital, Kaohsiung, Taiwan. 2. Department of Obstetrics and Gynecology, Chung Shan Medical University Hospital, 110, Jianguo N Rd, Section 1, Taichung, 402, Taiwan. gdchentw@hotmail.com. 3. Department of Women's Health, Dell Medical School, The University of Texas at Austin, Austin, TX, USA.