[1] Childrens Hosp, Sect Neonatol, Aurora, CO 80045 USA
[2] Univ Colorado, Denver Sch Med, Colorado Sch Publ Hlth, Aurora, CO 80045 USA
[3] Chinese Ctr Dis Control & Prevent, Natl Ctr Women & Childrens Hlth, Beijing 100089, Peoples R China
[4] Peking Univ Third Hosp, Dept Pediat, Beijing 100191, Peoples R China
[5] Tsinghua Univ First Hosp, Dept Pediat, Beijing 100016, Peoples R China
[6] Capital Med Univ, Beijing Obstet & Gynecol Hosp, Dept Obstet, Beijing 100026, Peoples R China
[7] Peking Union Med Coll Hosp, Dept Pediat, Beijing 100730, Peoples R China
[8] Peking Univ First Hosp, Dept Pediat, Beijing 100034, Peoples R China
[9] St Louis Univ, Cardinal Glennon Childrens Hosp, St Louis, MO USA
[10] St Louis Univ, Sch Med, St Louis, MO USA