[1] CHA Univ, Sch Med, CHA Gangnam Med Ctr, Dept Obstet & Gynecol, Seoul, South Korea
[2] Seoul Natl Univ, Bundang Hosp, Dept Obstet & Gynecol, Seongnam, South Korea
[3] Catholic Univ Korea, Seoul St Marys Hosp, Dept Obstet & Gynecol, Seoul, South Korea
[4] Sungkyunkwan Univ, Samsung Med Ctr, Sch Med, Dept Obstet & Gynecol, Seoul, South Korea
[5] Seoul Natl Univ, Seoul Metropolitan Govt, Boramae Med Ctr, Dept Obstet & Gynecol, Seoul, South Korea
[6] Catholic Kwandong Univ, Int St Marys Hosp, Coll Med, Dept Obstet & Gynecol, Incheon, South Korea
[7] CHA Univ, CHA Bundang Med Ctr, Dept Obstet & Gynecol, Div Gynecol Oncol, Seoul, South Korea
[8] Sungkyunkwan Univ Med, Samsung Changwon Hosp, Dept Obstet & Gynecol, Chang Won, South Korea
[9] Kyungpook Natl Univ, Sch Med, Dept Obstet & Gynecol, Daegu, South Korea
[10] Pusan Natl Univ, Sch Med, Dept Obstet & Gynecol, Yangsan, South Korea