1 Department of Obstetrics and Gynecology, National Hospital Organization, Shikoku Medical Center for Children and Adults, 2-1-1 Senyu-cho, Zentsuji, Kagawa, 765-8507, Japan. sikakajyositakaaki@yahoo.co.jp.
2 Department of Obstetrics and Gynecology, National Hospital Organization, Shikoku Medical Center for Children and Adults, 2-1-1 Senyu-cho, Zentsuji, Kagawa, 765-8507, Japan.