[1] Ditmanson Med Fdn Chia Yi Christian Hosp, Ctr Qual Management, Chiayi, Taiwan
[2] Ditmanson Med Fdn Chia Yi Christian Hosp, Dept Obstet & Gynecol, Chiayi, Taiwan
[3] Ditmanson Med Fdn Chia Yi Christian Hosp, Dept Med Res, Chiayi, Taiwan
[4] Taiwan Adventist Hosp, Dept Obstet & Gynecol, Taipei, Taiwan
[5] Natl Yang Ming Univ, Inst Hlth & Welf Policy, Sch Med, 155,Sec 2,Li Nong St, Taipei 112, Taiwan