[1] Sichuan Univ, West China Hosp, West China Sch Nursing, Chengdu 610041, Sichuan, Peoples R China
[2] Sichuan Univ, West China Hosp 2, Key Lab Birth Deficits & Related Dis Women & Chil, Chengdu 610041, Sichuan, Peoples R China
[3] Sichuan Univ, West China Hosp, Dept Orthoped, Chengdu 610041, Sichuan, Peoples R China
[4] Chongqing Med Univ, Childrens Hosp, Res Dept, Chongqing 401147, Peoples R China
[5] Xia Men Univ, Xiangan Hosp, Dept Radiol, Xiamen 361101, Fujian, Peoples R China