1. Department of Obstetrics and Gynecology, Tongji University School of Medicine, Shanghai Tenth People’s Hospital, Shanghai, China
2. School of Life Sciences and Technology, Tongji University, Shanghai, China
3. Department of Reproductive Medicine Center, Tongji University School of Medicine, Shanghai East Hospital, Shanghai, China
4. Department of Health Management, Tongji University School of Medicine, Shanghai East Hospital, Shanghai, China
5. School of Mathematics and Statistics, University of Glasgow, Glasgow, UK