[1] Sichuan Acad Med Sci, Dept Gynecol & Obstet, 32 West Second Sect,First Ring Rd, Chengdu, Sichuan, Peoples R China
[2] Sichuan Prov Peoples Hosp, 32 West Second Sect,First Ring Rd, Chengdu, Sichuan, Peoples R China
[3] West China Second Univ Hosp, Dept Gynecol & Obstet, 17,Sect 3,Renmin South Rd, Chengdu, Sichuan, Peoples R China
[4] Sichuan Univ, 17,Sect 3,Renmin South Rd, Chengdu, Sichuan, Peoples R China