1. Department of Obstetrics and GynecologySakakibara Heart Institute Fuchu Japan
2. Department of Perinatology and GynecologyNational Cerebral and Cardiovascular Center Osaka Japan
3. Department of Preventive Medicine and Public HealthKeio University Tokyo Japan
4. Department of Preventive CardiologyNational Cerebral and Cardiovascular Center Osaka Japan
5. Department of Obstetrics and GynecologyMie University Tsu Japan