1. The Reproductive Medical Center, Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, China
2. West China School of Medicine, Sichuan University, Chengdu, China
3. Key Laboratory of Birth Defects and Related of Women and Children of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, China
4. Information Management Department, West China Second University Hospital, Sichuan University, Chengdu, China
5. Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, China
6. Department of Outpatients, West China Second University Hospital, Sichuan University, Chengdu, China