1. Clinical Research Unit, Obstetrics and Gynecology Hospital, Fudan University, Shanghai, China.
2. Laboratory for Reproductive Immunology, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China.
3. Department of Obstetrics and Gynecology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
4. School of Public Health, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, Shandong, China.