1. Department of Urology Peking University Third Hospital Beijing China
2. Department of Reproductive Medicine Center Peking University Third Hospital Beijing China
3. Department of Andrology Peking University Third Hospital Beijing China
4. Department of Human Sperm Bank Peking University Third Hospital Beijing China
5. Key Laboratory of Male Reproductive and Genetics National Health and Family Planning Commission (Family Planning Research Institute of Guangdong Province) Guangzhou China
6. Key Laboratory of Assisted Reproduction Department of Obstetrics and Gynecology Center for Reproductive Medicine Ministry of Education Peking University Third Hospital Beijing China