Forty years on: the effect of deprivation on growth in two Newcastle birth cohorts

BACKGROUND: This study used two prospective birth cohort studies from the same city to examine the extent to which deprivation gradients for height and weight have changed over 40 years. METHODS: Participants were 954 (86%) full term members of the Thousand Families (TF) 1947 and 3145 (99.9%) members of the Growth and Development Study (GDS) 1987-1988 Newcastle birth cohorts with both deprivation and growth data. Weights were available at birth, 6 months, and 1 year; weight and height at 4 (GDS only), 9, and 13 years (TF only), and in adulthood (TF only). These were stratified by level of deprivation, measured by Registrar's General social class in 1947 and area-based Townsend scores in 1987. RESULTS: Both cohorts had similar birth and infancy weights, but there was no gradient by deprivation level at birth or in infancy in the 1947 cohort, while the 1987 cohort showed a consistent gradient from birth onwards. Height had increased from the 1947 to the 1987 cohort, but both showed very similar deprivation gradients, equivalent to a 4-cm difference between the most and least affluent strata at age 9 years. Body mass index was similar for both cohorts and only showed a deprivation gradient in adulthood. CONCLUSIONS: We found no evidence of a changing influence of socioeconomic deprivation on growth in childhood, despite increases in mean height over a 40-year interval.