[1] Osaka Med Ctr, Dept Pediat Cardiol, Osaka, Japan
[2] Res Inst Maternal & Child Hlth, Osaka, Japan
[3] Osaka Univ Hosp, Intens Care Unit, Osaka 553, Japan
[4] Osaka Univ, Grad Sch Med, Dept Pediat Surg, Osaka, Japan
[5] Natl Ctr Child Hlth & Dev, Dept Maternal & Perinatal Med, Div Neonatol, Tokyo, Japan
[6] Natl Ctr Child Hlth & Dev, Dept Surg Subspecialties, Div Surg, Tokyo, Japan
[7] Kyushu Univ, Grad Sch Med Sci, Dept Pediat Surg Reprod & Dev Med, Fukuoka 812, Japan
[8] Nagoya Univ Hosp, Dept Maternal & Perinatal Care Ctr, Nagoya, Aichi, Japan
[9] Hyogo Coll Med Univ, Dept Pediat Surg, Nishinomiya, Hyogo, Japan
[10] Hokkaido Univ, Grad Sch Med, Dept Obstet & Gynecol, Sapporo, Hokkaido, Japan