1. Department of Obstetrics and Gynecology Nagoya University Graduate School of Medicine Nagoya Japan
2. Department of Obstetrics and Gynecology Nagoya Ekisaikai Hospital Nagoya Japan
3. Department of Obstetrics and Gynecology Japanese Red Cross Aichi Medical Center Nagoya Daiichi Hospital Nagoya Japan
4. Minami Clinic Komaki Japan
5. Department of Emergency and Critical Care Medicine Japanese Red Cross Aichi Medical Center Nagoya Daiichi Hospital Nagoya Japan
6. Division of Obstetrics and Gynecology Holy Spirit Hospital Nagoya Japan
7. Hashii Women's Hospital Kyoto Japan
8. Department of Emergency and Disaster Medical Systems, Graduate School of Medicine Kyoto Prefectural University of Medicine Kyoto Japan