1. West China Second University Hospital, Sichuan University , Chengdu , Sichuan 610041 , China
2. Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education , Chengdu , Sichuan 610041 , China
3. Department of Gynecology, Sichuan University , Chengdu , Sichuan 610041 , China