1. Department of Obstetrics and Gynecology, Osaka Medical College, Takatsuki, Osaka, Japan.
2. Keio University School of Medicine, Tokyo, Japan
3. Tokyo Medical Center, Meguro-ku, Tokyo, Japan.
4. Tenriyorozu Hospital, Tenri, Nara, Japan.
5. Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
6. Kyoto University Graduate School of Medicine, Kyoto, Kyoto, Japan.