[1] Ehime Univ, Grad Sch Med, Program Nursing Sci, 454 Shizukawa, Toon, Ehime 7910295, Japan
[2] Kyoto Womens Univ, Fac Data Sci, Higashiyama Ku, Kyoto 6058501, Japan
[3] Bunkyo Gakuin Univ, Dept Nursing, Bunkyo Ku, Tokyo 1138668, Japan
[4] Teikyo Univ, Fac Med Technol, Dept Nursing, Itabashi Ku, Tokyo 1738605, Japan
[5] Ohtaka Clin, Dept Obstet & Gynecol, Ichikawa, Chiba 2720826, Japan
[6] Makita Clin, Dept Obstet & Gynecol, Niiza, Saitama 3520021, Japan