作者单位:NorthShore Univ HealthSyst, Dept Pathol & Lab Med, 2560 Ridge Ave, Evanston, IL 60201 USA[1]Northwestern Univ, Dept Pediat, Ann & Robert H Lurie Childrens Hosp, Feinberg Sch Med,Div Neonatol[2]Utah State Off Med Examiner, 4451 2700 W, Taylorsville, UT 84129 USA[3]