[1] Dankook Univ, Coll Med, Dept Obstet & Gynecol, Cheil Gen Hosp, 17 Seoae Ro 1 Gil, Seoul 04619, South Korea
[2] Dankook Univ, Coll Med, Womens Healthcare Ctr, 17 Seoae Ro 1 Gil, Seoul 04619, South Korea
[3] Catholic Univ Korea, Coll Med, Seoul St Marys Hosp, Dept Obstet & Gynecol, 222 Banpo Daero, Seoul 06591, South Korea
[4] Korea Ctr Dis Control & Prevent, Natl Inst Hlth, Ctr Immunol & Pathol, Div AIDS, Cheongwon, South Korea
[5] Keimyung Univ, Dongsan Med Ctr, Dept Obstet & Gynecol, Daegu, South Korea
[6] Chonnam Natl Univ, Sch Med, Dept Obstet & Gynecol, Gwangju, South Korea
[7] Dankook Univ, Coll Med, Cheil Gen Hosp, Dept Pathol, Seoul, South Korea
[8] Inje Univ, Coll Med, Inje Univ Busan Paik Hosp, Dept Obstet & Gynecol, Busan, South Korea
[9] Catholic Univ Korea, Coll Med, Dept Prevent Med, Seoul, South Korea