Corresponding author:
Eiji Shibata, MD, PhD
Department of Obstetrics and Gynecology, School of Medicine, University of Occupational and Environmental Health, Japan. Yahatanishi-ku, Kitakyushu 807-8555, Japan,
TEL: +81-93-603-1611
FAX: +81-93-691-9337
E-mail: age-s@med.uoeh-u.ac.jp