[1] Ewha Womans Univ, Dept Obstet & Gynecol, MokDong Hosp, Seoul 158051, South Korea
[2] Eulji Med Coll, Dept Obstet & Gynecol, Taejon, South Korea
[3] Ewha Womans Univ, Dept Prevent Med, Seoul, South Korea
[4] Ewha Womans Univ, Med Res Ctr, Seoul, South Korea
[5] GenDix Inc, Seoul, South Korea