title: [Differences between reference charts of weight in children up to the age of 18 months].
abstract: BACKGROUND
  Growth is a complex phenomenon that has in pediatric age special relevancy because it constitutes a fundamental indicator of nutritional status.
  
  
  OBJECTIVE
  To evaluate differences about weight analysis of infants aged 0-18 months depending on the population reference used.
  
  
  METHODS
  This is a longitudinal weight and length study in a representative sample of 383 infants from Aragon since birth until 18 months of age. A descriptive analysis was realized and "z-scores" were calculated from five growth curves. Finally there was calculated the percentage of children who were staying above or under 2DS for weight depending on the standard used.
  
  
  RESULTS
  50.1% were males and 49.9% women. Weight and length of the children were higher in girls than in boys in all the ages (p<0.01). Major differences between weight z-score averages from standards were at 6 months and later. The percentage of children on a weight<2 DS ranged between 0.5 and one 3.3% at 18 months of age depending on the standard.
  
  
  CONCLUSIONS
  Global differences exist when weight is evaluated in the same sample of infants up to 18 months of age depending on different population standards, as well as in the number of children who stay out of the limits of the normality with each of them.
authors.affiliation: Hospital Clínico Universitario Lozano Blesa, and Growth, Exercise, Nutrition and Development Research Group, Departamento de Pediatría, Radiología y Med. Física, Universidad de Zaragoza, Zaragoza, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Ayerza Casas
authors.forename: G
authors.initials: G
authors.lastname: Rodríguez Martínez
authors.forename: Ma P
authors.initials: MP
authors.lastname: Samper Villagrasa
authors.forename: J
authors.initials: J
authors.lastname: Fuertes Fernández-Espinar
authors.forename: P
authors.initials: P
authors.lastname: Broto Cosculluela
authors.forename: Ma P
authors.initials: MP
authors.lastname: Collado Hernández
authors.forename: M F
authors.initials: MF
authors.lastname: Sebastián Bonel
authors.forename: A B
authors.initials: AB
authors.lastname: Solanas Galindo
authors.forename: C
authors.initials: C
authors.lastname: Pardos Martínez
mesh_terms: D001827:Body Height / Q000502:physiology; D001835:Body Weight / Q000502:physiology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D009752:Nutritional Status; D012016:Reference Values; D013030:Spain / Q000453:epidemiology