[1] Nagoya Univ Hosp, Div Neonatol, Ctr Maternal Neonatal Care, Nagoya, Aichi 4668560, Japan
[2] Japanese Red Cross Nagoya First Hosp, Dept Neonatol, Nagoya, Aichi, Japan
[3] Kyushu Univ, Dept Pediat Surg, Grad Sch Med Sci, Fukuoka 812, Japan
[4] Shizuoka Childrens Hosp, Dept Pediat Surg, Shizuoka, Japan
[5] Hyogo Prefectural Kobe Childrens Hosp, Dept Pediat Surg, Kobe, Hyogo, Japan
[6] Kanagawa Childrens Med Ctr, Dept Surg, Yokohama, Kanagawa, Japan
[7] Osaka Med Ctr, Dept Neonatol, Tokyo, Japan
[8] Res Inst Maternal & Child Hlth, Tokyo, Japan
[9] Natl Ctr Child Hlth & Dev, Div Neonatol, Ctr Maternal Fetal & Neonatal Med, Tokyo, Japan
[10] Nihon Univ, Sch Med, Dept Pediat Surg, Tokyo, Japan
[11] Anjo Kosei Hosp, Dept Pediat, Anjo, Japan
[12] Osaka City Univ, Dept Publ Hlth, Fac Med, Osaka 558, Japan
[13] Osaka Univ, Dept Pediat Surg, Grad Sch Med, Suita, Osaka, Japan
[14] Hyogo Coll Med, Dept Pediat Surg, Nishinomiya, Hyogo 6638501, Japan