1. Department of Obstetrics and Gynecology; Yokohama City University Medical Center; 4-57 Urafunecho, Minami Ward 232-0024 Yokohama Kanagawa Japan
2. Department of Urology; Yokohama City University Medical Center; 4-57 Urafunecho, Minami Ward 232-0024 Yokohama Kanagawa Japan
3. Department of Obstetrics and Gynecology; Yokohama City University; 3-9 Fukuura, Kanazawa Ward 236-0004 Yokohama Kanagawa Japan