Social class difference in catch up growth in a national British cohort.

AIM To examine the influence of socioeconomic status on growth pattern in height from age 7 to 23 years. METHODS Prospective cohort study. A total of 10 200 white singleton born children from the 1958 British birth cohort (National Child Development Study) were analysed. RESULTS Differences in height by birth weight persisted throughout the follow up period. However, the mean differences in height between low birth weight infants (<2500 g) and adequate birth weight infants (>/=2500 g) were less notable in social classes I and II than in the lower social classes. The catching up of growth in height of low birth weight infants was also more pronounced in social classes I and II than in other social classes. That is, the mean height deficits of low birth weight infants were decreased from 2.9 cm at age 7, to 1.6 cm at age 16, and 2.5 cm at age 23; the significant difference disappeared after age 16 in social classes I and II. Although such improving tendency was more pronounced among the preterm born infants, a similar growth pattern was observed among the term infants. Such improvement was not observed in the other social classes. CONCLUSION The growth retardation in height by birth weight can be overcome by improved social conditions and proper health care from childhood to adulthood.