[1] Chinese Acad Med Sci, Peking Union Med Coll, Peking Union Med Coll Hosp, Dept Obstet & Gynecol, Beijing 100730, Peoples R China
[2] Tsinghua Univ, Sch Life Sci, Technol Ctr Prot Sci, Beijing 100084, Peoples R China
[3] Hebei Med Univ, Hosp 2, Dept Obstet & Gynecol, Shijiazhuang 050000, Hebei, Peoples R China
[4] Cent S Univ, Xiangya Hosp 3, Dept Obstet & Gynecol, Changsha 410013, Hunan, Peoples R China
[5] Capital Med Univ, Beijing Chaoyang Hosp, Dept Obstet & Gynecol, Beijing 100020, Peoples R China