1. Center for Reproductive Medicine, Shandong University, Jinan, 250012 Shandong, China
2. Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, 250012 Shandong, China
3. Shandong Key Laboratory of Reproductive Medicine, Jinan, 250012 Shandong, China
4. Shandong Provincial Clinical Research Center for Reproductive Health, Jinan, 250012 Shandong, China
5. The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012 Shandong, China