1. Department of Gynecology and Obstetrics, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong 519000, China
2. Department of Gynecology and Obstetrics, The Seventh Affiliated Hospital of Sun Yat-Sen University, Shenzhen, Guangdong 518000, China
3. Medical Record Department, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong 519000, China