title: [Age for sitting and walking in children born weighing less than 1,500 g and normal motor development at two years of age].
abstract: OBJECTIVE
  To estimate the corrected age (CA) of acquisition of sitting and walking in very low birth weight infants with normal motor outcome at 2 years of age and to determine whether transient hypertonia is associated with a delay in the acquisition of sitting and walking.
  
  
  METHODS
  Follow-up study of very low birth weight infants (under 1500 g) admitted to the Neonatology Department of the Hospital 12 de Octubre from January 1991 to December 1996. At 2 years of age, 260 infants had normal motor outcome and 36% of these had been diagnosed with transient hypertonia. The age at which sitting and walking were attained was recorded by interview with the parents and was confirmed by examination.
  
  
  RESULTS
  The mean CA at which sitting was attained was 7.2 +/- 1.4 months. Ninety percent of the infants had acquired sitting at a CA of 9 months. Mean age at which walking was attained was 13.4 +/- 2.8 months. Ninety percent could walk at 16 months. Infants with and without transient hypertonia acquired sitting and walking at the same age.
  
  
  CONCLUSIONS
  Ninety percent of very low birth weight infants attained sitting at a CA of 9 months and walking at a CA of 16 months. Transient hypertonia did not modify the pattern of sitting and walking and it could be considered a variation of normality within the development of very premature infants.
authors.affiliation: Servicio de Neonatología, Hospital 12 de Octubre, Madrid. jdlcruz@h12o.es
authors.forename: C R
authors.initials: CR
authors.lastname: Pallás Alonso
authors.forename: J
authors.initials: J
authors.lastname: de La Cruz Bértolo
authors.forename: M C
authors.initials: MC
authors.lastname: Medina López
authors.forename: G
authors.initials: G
authors.lastname: Bustos Lozano
authors.forename: C
authors.initials: C
authors.lastname: de Alba Romero
authors.forename: R
authors.initials: R
authors.lastname: Simón De Las Heras
mesh_terms: D000367:Age Factors; D002657:Child Development; D005260:Female; D005500:Follow-Up Studies; D006128:Growth; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D008297:Male; D009048:Motor Skills; D016138:Walking