Department of Gynecology and Obstetrics The Second Affiliated Hospital Sun Yat-sen University Guangzhou 510120 China;
Department of Gynecology and Obstetrics The Second Affiliated Hospital Sun Yat-sen University Guangzhou 510120 China;
Department of Gynecology and Obstetrics The Second Affiliated Hospital Sun Yat-sen University Guangzhou 510120 China;
Department of Gynecology and Obstetrics The Second Affiliated Hospital Sun Yat-sen University Guangzhou 510120 China;