1. Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
2. Zhengzhou Key Laboratory of Cervical Disease, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
3. National Clinical Research Center for Obstetrics and Gynecology, Henan Branch, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
4. Organ Transplant Center, Xiangya Hospital, Central South University, Changsha, China