1. Department of Obstetrics and Gynecology, Center for Reproductive Medicine, Peking University Third Hospital, HaiDian District, Beijing, China
2. Department of Obstetrics and Gynecology, Center for Reproductive Medicine, Peking University Shenzhen Hospital, FuTian District, Shenzhen, Guangdong, China
3. Beijing Key Laboratory of Reproductive Endocrinology and Assisted Reproduction, Beijing, China
4. Department of Obstetrics and Gynecology, Center for Reproductive Medicine, Shengjing Hospital of China Medical University, Shenyang, China
5. Key Laboratory of Assisted Reproduction, Ministry of Education, Beijing, China