1. Department of Dermatovenereology, Tianjin Medical University General Hospital/Tianjin Institute of Sexually Transmitted Disease, Tianjin 300052, China
2. Obstetrics and Gynecology Department, Tianjin Medical University General Hospital, Tianjin 300052, China
3. Obstetrics and Gynecology Department, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325015, China.