[1] Dongguk Univ, Dept Korean Obstet & Gynecol, Ilsan Hosp Korean Med, Goyang, South Korea
[2] Dongguk Univ, Dept Obstet & Gynecol, Ilsan Hosp, Goyang, South Korea
[3] Dongguk Univ, Sch Med, Dept Biostat, Goyang, South Korea
[4] Kyung Hee Univ, Coll Korean Med, Dept Korean Gynecol, Seoul, South Korea
[5] Wonkwang Univ, Coll Korean Med, Dept Korean Gynecol, Iksan, South Korea