1. Deparment of Gynecology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000 China
2. Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, Hubei, 430022, PR China
3. Department of Gynecology, the Anyang Cancer Hospital, the Fourth Affiliated Hospital of Henan University, Anyang, 455000 China