1. Department of Reproductive Health Nursing/Midwifery; Nagoya City University Graduate School of Nursing; Nagoya Japan
2. Department of Community Health and Preventive Medicine; Shizuoka Japan
3. Department of Medical Physiology; Hamamatsu University School of Medicine; Shizuoka Japan
4. Department of Obstetrics and Gynecology; Hamamatsu Medical Center; Shizuoka Japan