1. Division of Microbiology, Department of Pathology and Microbiology, Nihon University School of Medicine, Tokyo 173-8610, Japan
2. Institute of Journalism and Media, Nihon University, Tokyo 101-8375, Japan
3. Integrated Research Faculty for Advanced Medical Sciences, Dokkyo Medical University, Tochigi 321-0293, Japan
4. Department of Obstetrics and Gynecology, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
5. College of Risk Management, Nihon University, Tokyo 154-8513, Japan
6. Division of Obstetrics and Gynecology, Nihon University School of Medicine, Tokyo 173-8610, Japan
7. Department of Public Health, Dokkyo Medical University, Tochigi 321-0293, Japan
8. Department of Obstetrics and Gynecology, Yokohama City University Hospital, Yokohama 236-0004, Japan
9. Center for Recurrent Pregnancy Loss, Teine Keijinkai Hospital, Sapporo 006-8555, Japan
10. Department of Obstetrics and Gynecology, Ehime University Graduate School of Medicine, Toon 791-0295, Japan