1. Department of Reproductive Medicine, The Fourth Hospital of Hebei Medical University , Shijiazhuang 050041, Hebei Province , China
2. Hebei Chest Hospital , Shijiazhuang 050041, Hebei Province , China
3. Department of Gynaecology, The Fourth Hospital of Hebei Medical University , Shijiazhuang 050041, Hebei Province , China
4. Shenzhou People’s Hospital , Shenzhou , 053800, Hebei Province , China
5. Department of Gynaecology, The Fourth Hospital of Hebei Medical University , No. 12, Jiankang Road , Shijiazhuang 050041, Hebei Province , China