1. Department of Gynecology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, Guangdong Province, P.R. China
2. Reproductive Medicine Center, The Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou 510655, Guangdong Province, P.R. China
3. Department of Radiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, Guangdong Province, P.R. China
4. Department of nephrology, The Second Xiangya Hospital, Central South University, Changsha 410001, Hunan Province, P.R. China