1. Department of Gynecology, Central Hospital of Zibo in Shandong, Zibo, Shandong, China (mainland)
2. Department of Gynecology, People’s Hospital of ZhangQiu in Shandong Province, Zhangqiu, Shandong, China (mainland)
3. Department of Gynecology, Third Ward, People’s Hospital of Linyi City, Linyi, Shandong, China (mainland)