title: [To born small for gestational age may depend on the growth curve used].
abstract: OBJECTIVE
  Population standards of intrauterine growth are necessary to evaluate if the newborn has grown well, if their nutritional conditions are appropriate and to identify groups at risk as those small for gestational age (SGA). Differences in the number of SGA newborns identified, depending on the standard applied, have been analyzed in this study.
  
  
  METHODS
  Cross-sectional study conducted in 4,486 Caucasian newborns (2,361 boys and 2,125 girls), born between 35 and 41 weeks. Weight and length valuation was performed following the standard methodology. Percentage of children under the 10(th) percentile for weight and length was calculated depending on the standard used (Olsen et al. 2010, Lubchenco et al. 1966, Delgado et al. 1996, Carrascosa et al. 2008), being diagnosed of SGA.
  
  
  RESULTS
  Weight and length were significantly higher in boys than in girls at all ages. 10(th) percentile values defined for every gestational age are globally similar among the different standards and our population, with the clear exception of Lubchenco curves whose 10(th) percentile values are even 300 g. lower for the newborns at the highest gestational ages. Lubchenco charts do not fit the pattern of intrauterine growth of our population and identify a smaller number of SGA. The percentage of SGA of our sample ranged between 1.7% and 14% in depending on the standard, sex and gestational age considered.
  
  
  CONCLUSIONS
  The number of children classified as SGA is different according to each standard used. Lubchenco charts identify a smaller number of SGA than the others. The rest of curves show similar values and seem to be well adapted for our population. The correct identification of SGA will allow a better assessment of short and long-term risks of these newborns.
authors.affiliation: Hospital Clínico Universitario Lozano Blesa, Zaragoza, España.
authors.forename: A
authors.initials: A
authors.lastname: Ayerza Casas
authors.forename: G
authors.initials: G
authors.lastname: Rodríguez Martínez
authors.forename: M P
authors.initials: MP
authors.lastname: Samper Villagrasa
authors.forename: P
authors.initials: P
authors.lastname: Ventura Faci
mesh_terms: D000367:Age Factors; D001827:Body Height / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D003430:Cross-Sectional Studies; D005260:Female; D005317:Fetal Growth Retardation / Q000453:epidemiology; D005865:Gestational Age; D057238:Growth Charts; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age / Q000502:physiology*; D008297:Male; D011247:Pregnancy; D012015:Reference Standards; D012307:Risk Factors; D012737:Sex Factors