[1] Peking Univ First Hosp, Dept Pediat, 1 Xian Men St, Beijing 100034, Peoples R China
[2] Tianjin Cent Hosp Gynecol Obstet, Dept Neonatol, Tianjin 300100, Peoples R China
[3] Peking Univ Third Hosp, Dept Pediat, Beijing 100191, Peoples R China
[4] Childrens Hosp Shanxi, Neonatal Intens Care Unit, Taiyuan 030031, Shanxi, Peoples R China
[5] Hebei Med Univ, Dept Neonatol, Hosp 2, Shijiazhuang 050000, Hebei, Peoples R China
[6] Handan Cent Hosp, Dept Neonatol, Handan 056004, Hebei, Peoples R China
[7] Xingtai Peoples Hosp, Dept Neonatol, Xingtai 054031, Hebei, Peoples R China
[8] Tangshan Maternal & Child Hlth Hosp, Dept Neonatol, Tangshan 071023, Hebei, Peoples R China
[9] Tianjin Med Univ, Dept Pediat, Gen Hosp, Tianjin 300052, Peoples R China
[10] Baogang Third Hosp, Dept Pediat, HongCi Grp, Baotou 014010, Inner Mongolia, Peoples R China
[11] Chengde Med Univ, Dept Neonatol, Affiliated Hosp, Chengde 067000, Hebei, Peoples R China
[12] Tsinghua Univ, Dept Pediat, Hosp 1, Beijing 100016, Peoples R China
[13] Inner Mongolia Med Univ, Dept Neonatol, Affiliated Hosp, Hohhot 010050, Inner Mongolia, Peoples R China
[14] Inner Mongolia Maternal & Child Hlth Hosp, Dept Neonatol, Hohhot 010020, Inner Mongolia, Peoples R China
[15] Chifeng Univ, Dept Neonatol, Affiliated Hosp, Chifeng 024005, Inner Mongolia, Peoples R China
[16] Peking Univ, Dept Pediat, Peoples Hosp, Beijing 100044, Peoples R China
[17] Hebei Childrens Hosp, Dept Neonatol, Shijiazhuang 050000, Hebei, Peoples R China
[18] Tianjin First Cent Hosp, Dept Neonatol, Tianjin 300384, Peoples R China
[19] Peking Union Med Coll Hosp, Dept Pediat, Beijing 100730, Peoples R China
[20] Childrens Hosp Capital Inst Pediat, Dept Neonatol, Beijing 100020, Peoples R China
[21] Capital Med Univ, Dept Pediat, Beijing Luhe Hosp, Beijing 101149, Peoples R China
[22] Capital Med Univ, Dept Pediat, Beijing Friendship Hosp, Beijing 100050, Peoples R China
[23] Chifeng Municipal Hosp, Dept Neonatol, Chifeng 024099, Inner Mongolia, Peoples R China
[24] Capital Med Univ, Beijing Childrens Hosp, Neonatal Ctr, Beijing 100045, Peoples R China
[25] Zhangjiakou Maternal & Child Hlth Hosp, Dept Neonatol, Zhangjiakou 075001, Hebei, Peoples R China
[26] Xing An Meng Hosp Inner Mongolia, Dept Neonatol, Xing An Meng 137499, Inner Mongolia, Peoples R China
[27] Tianjin Med Univ, Dept Neonatol, Hosp 2, Tianjin 300211, Peoples R China
[28] Taiyuan Maternal & Child Hlth Hosp, Dept Neonatol, Taiyuan 030021, Shanxi, Peoples R China
[29] Beijing United Family Hosp, Neonatal Intens Care Unit, Beijing 100016, Peoples R China
[30] PLA Rocket Force Characterist Med Ctr, Dept Gynecol & Pediat, Beijing 100088, Peoples R China
[31] Fenyang Hosp Shanxi, Dept Neonatol, Fenyang 030009, Shanxi, Peoples R China
[32] Baoding Maternal & Child Hlth Hosp, Dept Neonatol, Baoding 071023, Hebei, Peoples R China
[33] Chaoyang Maternal & Child Hlth Hosp Beijing, Dept Pediat, Beijing 100024, Peoples R China