[1] Natl Ctr Child Hlth & Dev NCCHD, Div Neonatol, Tokyo, Japan
[2] Int Cathol Hosp, Obstet & Gynecol, Tokyo, Japan
[3] Saitama Med Univ, Dept Pediat, Saitama Med Ctr, Saitama, Japan
[4] Keio Univ, Dept Pediat, Sch Med, Tokyo, Japan
[5] Nihon Univ, Dept Pediat & Child Hlth, Sch Med, Tokyo, Japan
[6] Osaka Womens & Childrens Hosp, Dept Maternal Fetal Med, Izumi, Japan
[7] Miyagi Childrens Hosp, Dept Maternal Fetal Med, Sendai, Miyagi, Japan
[8] Nihon Univ, Dept Pediat Surg, Sch Med, Itabashi Ku, Tokyo, Japan
[9] Niigata Univ, Dept Pediat Surg, Grad Sch Med & Dent Sci, Niigata, Japan
[10] Natl Hosp Org Nagasaki Med Ctr, Dept Obstet & Gynecol, Nagasaki, Japan
[11] Kansai Med Univ, Dept Anesthesiol, Hirakata, Osaka, Japan
[12] Tokai Univ, Sch Med, Dept Pediat, Isehara, Kanagawa, Japan
[13] Showa Univ, Koto Toyosu Hosp, Dept Obstet & Gynecol, Koto Ku, Tokyo, Japan