1. Department of Obstetrics and Gynecology West China Second University Hospital Sichuan University Chengdu China
2. Laboratory of Birth Defects and Related Diseases of Women and Children (Ministry of Education) Sichuan University Chengdu China
3. West China Medical Center Sichuan University Chengdu China
4. Department of Obstetrics and Gynecology Mianyang Central Hospital Mianyang China
5. Department of Obstetrics and Gynecology The Third Affiliated Hospital of Chengdu Medical College Chengdu China
6. Department of Obstetrics and Gynecology Enshi Clinical College of Wuhan University Enshi China