1. Department of Obstetrics and Gynecology; The Affiliated Yantai Yuhuangding Hospital of Qingdao University; Yantai Shandong Province China
2. Department of Obstetrics and Gynecology; The First Affiliated Hospital of Nanjing Medical University; Nanjing JiangSu Province China
3. Department of General Surgery; The Affiliated Yantai Yuhuangding Hospital of Qingdao University; Yantai Shandong Province China