1. Department of Obstetrics and Gynecology, Tohoku University
2. Miyagi Prefecture Branch, Japanese Medical Association of Obstetrics and Gynecology
3. National Sendai Hospital
4. Tohoku Kousai Hospital
5. Sendai Municipal Hospital
6. Sendai Red Cross Hospital
7. Furukawa Municipal Hospital
8. Sanuma Municipal General Hospital
9. Miyako Prefectial Hospital
10. Suzuki Hospital
11. Nakagawa Obstetrics and Gynecology Hospital