title: A gestation- and postnatal age-based reference chart for assessing renal function in extremely premature infants.
abstract: OBJECTIVE
  A single value of plasma creatinine cannot be used to define renal dysfunction in premature babies, as levels are influenced by gestation and postnatal age. The aim of this study was to create reference ranges for plasma creatinine in cohort of extremely premature infants.
  
  
  METHODS
  Retrospective analysis of plasma creatinine levels in the first 8 weeks of life from 161 consecutively admitted premature infants 28 weeks gestation.
  
  
  RESULTS
  Babies were divided into three groups according to gestation. Peak (10th, 90th percentiles) creatinine levels were 132 (106,162) in 22 to 24 weeks gestational infants, 127 (89,151) in those from 25 to 26 weeks and 110 (87,134) in those from 27 to 28 weeks (P<0.001). Creatinine at birth was similar across the groups with levels increasing during the first few days. It decreases thereafter before reaching stable levels by 5 weeks of age.
  
  
  CONCLUSIONS
  Gestation- and age-based reference charts should be used for interpretation of creatinine values in extremely premature babies.
authors.affiliation: Department of Cardiovascular Imaging, Great Ormond Street Hospital, UCL Institute of Child health, London, UK. s.thayyil@ich.ucl.ac.uk
authors.forename: S
authors.initials: S
authors.lastname: Thayyil
authors.forename: S
authors.initials: S
authors.lastname: Sheik
authors.forename: S T
authors.initials: ST
authors.lastname: Kempley
authors.forename: A
authors.initials: A
authors.lastname: Sinha
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis; D003404:Creatinine / Q000097:blood*; D005919:Glomerular Filtration Rate; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000097:blood / Q000175:diagnosis*; D012016:Reference Values; D014508:Urea / Q000097:blood
chemical_list: D014508:Urea; D003404:Creatinine