[1] Sakakibara Heart Inst, Dept Obstet & Gynecol, Tokyo, Japan
[2] Mie Univ, Dept Obstet & Gynecol, Sch Med, Tsu, Mie, Japan
[3] St Marianna Univ, Dept Obstet & Gynecol, Sch Med, Kawasaki, Kanagawa, Japan
[4] Hamamatsu Univ, Dept Obstet & Gynecol, Sch Med, Hamamatsu, Shizuoka, Japan
[5] Toho Univ, Dept Obstet & Gynecol, Tokyo, Japan
[6] Seirei Hamamatsu Gen Hosp, Maternal & Perinatal Care Ctr, Div Perinatol, Hamamatsu, Shizuoka, Japan
[7] Showa Univ, Dept Obstet & Gynecol, Sch Med, Tokyo, Japan
[8] Ishiwata Obstet & Gynecol Hosp, Ibaraki, Japan
[9] Natl Ctr Child Hlth & Dev, Dept Hlth Policy, Tokyo, Japan
[10] Kindai Univ, Nara Hosp, Dept Diagnost Pathol, Fac Med, Ikoma, Japan
[11] Osaka Med Ctr, Dept Pathol, Izumi, Japan
[12] Res Inst Maternal & Child Hlth, Izumi, Japan
[13] Natl Cerebral & Cardiovasc Ctr, Dept Perinatol, Osaka, Japan