1. Center for Reproductive Medicine, Shandong University National Research Center for Assisted Reproductive Technology and Reproductive Genetics, The Key Laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China;
2. Key Laboratory of Assisted Reproduction, Ministry of Education, Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, China;
3. Ren Ji Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China