[1] Guangzhou Med Univ, Guangdong Prov Key Lab Major Obstetr Dis, Dept Infect Dis, Guangzhou, Peoples R China
[2] Guangzhou Med Univ, Guangdong Prov Clin Res Ctr Obstet & Gynecol, Affiliated Hosp 3, Guangzhou, Peoples R China
[3] Guangzhou Med Univ, Affiliated Hosp 3, Dept Clin Res Management Off, Guangzhou, Peoples R China
[4] Guangzhou Med Univ, Affiliated Hosp 3, Dept Obstet & Gynecol, Guangzhou, Peoples R China
[5] Guangzhou Obstet Crit Care Ctr, Key Lab Major Obstet Dis Guangdong Prov, Guangzhou, Peoples R China