1. Department of Obstetrics and Gynecology, Institute of Health Biosciences, Tokushima University Graduate School, Tokushima, Japan
2. Department of Gynecology, Iseikai Hospital, Osaka Japan
3. Department of Obstetrics and Gynecology, Tokushima Red Cross Hospital, Tokushima, Japan
4. Department of Obstetrics and Gynecology, Tokushima Prefectural Central Hospital, Tokushima, Japan