[1] Seoul Natl Univ, Dept Obstet & Gynecol, Coll Med, 101 Daehak Ro, Seoul 03080, South Korea
[2] Univ Ulsan, Asan Med Ctr, Dept Obstet & Gynecol, Coll Med, Seoul, South Korea
[3] Korea Inst Sci & Technol, Mol Recognit Res Ctr, 5 Hwarang Ro 14 Gil, Seoul 02792, South Korea
[4] Seoul Natl Univ, Boramae Med Ctr, Dept Obstet & Gynecol, Seoul Metropolitan Govt, Seoul, South Korea
[5] Seoul Womens Hosp, Incheon, South Korea
[6] Seoul Natl Univ, Dept Lab Med, Coll Med, Seoul, South Korea
[7] Seoul Natl Univ, Boramae Med Ctr, Dept Lab Med, Seoul Metropolitan Govt, Seoul, South Korea
[8] Seoul Natl Univ, Dept Internal Med, Coll Med, Seoul, South Korea
[9] Seoul Natl Univ, Boramae Med Ctr, Seoul Metropolitan Govt, Dept Internal Med, Seoul, South Korea
[10] Tufts Univ, Sch Med, Dept Obstet & Gynecol, Boston, MA 02111 USA