1 Department of Obstetrics and Gynecology, University of Occupational and Environmental Health School of Medicine, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyusyu 807-8555, Japan.
2 Department of Pathology-1, University of Occupational and Environmental Health School of Medicine, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyusyu 807-8555, Japan.