Children with intellectual or developmental disability have significantly poorer health and mental health than their non-disabled peers and are at high risk of social exclusion. The aim of the present paper is to provide information on the circumstances in which 3-year-old children at risk of intellectual or developmental disability are growing up in the UK.

Secondary analysis of data on 12 689 families in English-speaking monolingual households from the first two waves of the UK's Millennium Cohort Study. A total of 440 children (3% of the weighted sample) were identified as being developmentally delayed.

When compared with other children, children with developmental delays were more disadvantaged on every indicator of social and economic disadvantage examined. Two out of three children with developmental delays had been exposed to repeated disadvantage as measured by income poverty, material hardship, social housing and receipt of means-tested benefits. The effect of repeated disadvantage on the risk of developmental delay remained after account was taken of parental education and occupational status.

Young children with delayed development in the UK are likely to be exposed to repeated socio-economic disadvantage. Implications for policy and understanding the nature of the link between poverty and child disability are discussed.