Hsiang-Tai Chao1, Peng-Hui Wang2. 1. Department of Obstetrics and Gynecology, National Yang-Ming University, Taipei, Taiwan; Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan. 2. Department of Obstetrics and Gynecology and Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Obstetrics and Gynecology, National Yang-Ming University Hospital, Ilan, Taiwan; Immunology Center, Taipei Veterans General Hospital, Taipei, Taiwan; Infection and Immunity Research Center, National Yang-Ming University, Taipei, Taiwan; Department of Medical Research, China Medical University Hospital, Taichung, Taiwan. Electronic address: phwang@vghtpe.gov.tw.