[1] Shijiazhuang Fourth Hosp, Perinatal Ctr, Shijiazhuang 050000, Hebei, Peoples R China
[2] Shijiazhuang Fourth Hosp, Obstet Dept, Shijiazhuang 050000, Hebei, Peoples R China
[3] Univ Kebangsaan Malaysia, UKM Med Mol Biol Inst, Kuala Lumpur, Malaysia