1. Department of Obstetrics and Gynecology Teine Keijinkai Hospital Sapparo Japan
2. Department of Obstetrics and Gynecology Tonami General Hospital Toyama Japan
3. Department of Obstetrics and Gynecology University of Yamanashi Yamanashi Japan
4. Department of Obstetrics and Gynecology Kurobe City Hospital Kurobe Japan
5. Center for Recurrent Pregnancy Loss Teine Keijinkai Hospital Sapporo Japan