[1] Kyushu Univ, Grad Sch Med Sci, Dept Pediat, Higashi Ku, Fukuoka 8128582, Japan
[2] Kyushu Univ Hosp, Matern & Perinatal Care Unit, Fukuoka 812, Japan
[3] Natl Kyushu Med Ctr, Dept Pediat, Fukuoka, Japan
[4] Fukuoka Municipal Childrens Hosp, Dept Neonatol, Fukuoka, Japan
[5] Kyushu Univ, Grad Sch Med Sci, Dept Obstet & Gynecol, Fukuoka 8128582, Japan
[6] Kyushu Univ, Grad Sch Med Sci, Dept Pediat Surg, Fukuoka 8128582, Japan