1. Department of Gynecology, the People’s Hospital of Qiannan, Duyun, Guizhou, P.R. China
2. Department of Obstetrics, the People’s Hospital of Qiannan, Duyun, Guizhou, P.R. China
3. Department of Plastic Surgery, the People’s Hospital of Qiannan, Duyun, Guizhou, P.R. China
4. Department of Anesthesiology, the People’s Hospital of Qiannan, Duyun, Guizhou, P.R. China.