[1] Hiroshima Univ, Grad Sch Biomed & Hlth Sci, Midwifery & Maternal Child Nursing, Hiroshima, Japan
[2] Hiroshima Univ, Hiroshima, Japan
[3] Prefectural Hosp Hiroshima, Dept Neonatol, Hiroshima, Japan
[4] Saitama Med Ctr, Ctr Maternal Fetal & Neonatal Med, Saitama, Japan
[5] Yamagata Prefectural Cent Hosp, Perinatal Ctr, Yamagata, Japan
[6] Tokyo Womens Med Univ, Dept Pediat Cardiol, Tokyo, Japan
[7] Japanese Red Cross Kyoto Daiichi Hosp, Dept Neonatol, Kyoto, Japan
[8] Nagoya Univ Hosp, Ctr Maternal Neonatal Care, Div Neonatol, Nagoya, Aichi, Japan
[9] Hiroshima City Hiroshima Citizens Hosp, Dept Gen Perinatol & Neonatol, Hiroshima, Japan