1. Department of Occupational and Environmental Health, College of Public Health, Zhengzhou University, Zhengzhou, China
2. Center for Reproductive Medicine, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
3. Key Laboratory of Reproductive Endocrinology, Ministry of Education, Shandong University, Jinan, China
4. National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China