[1] Sakakibara Heart Inst, Dept Obstet & Gynecol, 3-16-1 Asahicho, Fuchu, Tokyo 183003, Japan
[2] Natl Cerebral & Cardiovasc Ctr, Dept Perinatol & Gynecol, Osaka, Japan
[3] Keio Univ, Dept Prevent Med & Publ Hlth, Tokyo, Japan
[4] Natl Cerebral & Cardiovasc Ctr, Dept Prevent Cardiol, Suita, Osaka, Japan
[5] Mie Univ, Dept Obstet & Gynecol, Tsu, Mie, Japan