1. Department of Obstetrics and Gynecology, Aichi Medical University School of Medicine
2. Department of Obstetrics and Gynecology, Nara Medical University
3. Department of Obstetrics and Gynecology, Hirosaki University
4. Department of Obstetrics and Gynecology and Tohoku Medical Megabank Organization, Tohoku University
5. Department of Obstetrics and Gynecology, Nagoya City West Medical Center