[1] Seoul Natl Univ, Bundang Hosp, Dept Obstet & Gynecol, Songnam, South Korea
[2] Seoul Natl Univ, Coll Med, Dept Obstet & Gynecol, Seoul, South Korea
[3] Ajou Univ, Sch Med, Gynecol Canc Ctr, Dept Obstet & Gynecol, 164 Worldcup Ro, Suwon 16499, South Korea
[4] Univ Calif Irvine, Sch Med, Dept Obstet & Gynecol, Div Gynecol Oncol, Orange, CA USA