1. Department of Obstetrics and Gynecology, Kinki University Nara Hospital, 1248-1 Otuda-Chou, Ikoma, Nara 630-0293, Japan
2. Department of Obstetrics and Gynecology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8522, Japan
3. Department of Diagnostic Pathology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8522, Japan