1 Department of Obstetrics and Gynecology, West China Second University Hospital of Sichuan University, Chengdu, China; Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China.
2 Department of Obstetrics and Gynecology, West China Second University Hospital of Sichuan University, Chengdu, China; Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China. Electronic address: zjw6662023@163.com.