[1] CHA Univ, CHA Gangnam Med Ctr, Dept Obstet & Gynecol, Seoul 135081, South Korea
[2] Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Dept Obstet & Gynecol, Seoul, South Korea
[3] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Obstet & Gynecol, Seoul, South Korea
[4] Seoul Natl Univ, Bundang Hosp, Dept Obstet & Gynecol, Songnam, South Korea
[5] Catholic Univ Korea, Seoul St Marys Hosp, Dept Obstet & Gynecol, Seoul, South Korea
[6] Natl Canc Ctr, Res Inst & Hosp, Gynecol Canc Branch, Goyang, South Korea
[7] Natl Canc Ctr, Res Inst & Hosp, Ctr Uterine Canc, Goyang, South Korea
[8] SMG SNU Boramae Med Ctr, Dept Obstet & Gynecol, Seoul, South Korea