1. Department of Gynecology, The Secondary Hospital of Tianjin Medical University, No. 23 Pingjiang Road, Hexi District, Tianjin 300211, China
2. Department of Gynecology, Chifeng Municipal Hospital, Chifeng Clinical Medical School of Inner Mongolia Medical University, Chifeng 024099, China
3. Department of Gynecology Oncology, Tianjin Central Hospital of Gynecology & Obstetrics, 156 Sanmalu, Nankai, Tianjin 300100, China