1. Department of Obstetrics and Gynecology, Tokyo Dental College Ichikawa General Hospital, Sugano 5-11-13, Ichikawa-City, Chiba 272-8513, Japan
2. Department of Nursing Science, Hirosaki University Graduate School of Health Sciences, Zaifu-cho 5, Hirosaki-City, Aomori 036-8562, Japan
3. Division of Women’s Health, Research Institute of Traditional Asian Medicine, Kindai University, Oonohigashi 377-2, Osaka-sayama-City, Osaka 589-8511, Japan
4. Department of International/Community Health Laboratory Sciences, Graduate School of Health Sciences, Gunma University, Showa-Machi 3-39-22, Maebashi-city, Gunma 371-8514, Japan
5. Fukushima Medical Center for Children and Women, Fukushima Medical University, Hikariga-oka 1, Fukushima-City, Fukushima 960-1295, Japan