1. Department of Reproductive Medicine, The Fourth Hospital of Hebei Medical University , Shijiazhuang , 050011, Hebei , China
2. Department of Obstetrics, The Fourth Hospital of Hebei Medical University , Shijiazhuang , 050011, Hebei , China
3. Department of Gynecology, The Fourth Hospital of Hebei Medical University , Shijiazhuang , 050011, Hebei , China
4. Department of Gynecology, The Fourth Hospital of Hebei Medical University , No. 12 Jiankang Road , Shijiazhuang , 050011, Hebei , China