[1] Catholic Univ Korea, Seoul St Marys Hosp, Coll Med, Dept Obstet & Gynecol, Seoul, South Korea
[2] Catholic Univ Korea, St Vincents Hosp, Coll Med, Dept Obstet & Gynecol, Seoul, South Korea
[3] Catholic Univ Korea, Incheon St Marys Hosp, Coll Med, Dept Obstet & Gynecol, Seoul, South Korea
[4] Catholic Univ Korea, Bucheon St Marys Hosp, Coll Med, Dept Obstet & Gynecol, Seoul, South Korea
[5] Catholic Univ Korea, Eunpyeong St Marys Hosp, Coll Med, Dept Obstet & Gynecol, Seoul, South Korea
[6] Catholic Univ Korea, Uijeongbu St Marys Hosp, Coll Med, Dept Obstet & Gynecol, Seoul, South Korea
[7] Catholic Univ Korea, Yeouido St Marys Hosp, Coll Med, Dept Obstet & Gynecol, Seoul, South Korea
[8] Catholic Univ Korea, Daejeon St Marys Hosp, Coll Med, Dept Obstet & Gynecol, Seoul, South Korea
[9] Innerwave Co Ltd, Seoul, South Korea