The impact of episodic and chronic poverty on child cognitive development.

Objective: To determine whether changes in family poverty between pregnancy, early childhood, and adolescence predict child cognitive development at 14 years of age.
Study Design: We conducted a population-based prospective birth cohort study of 7223 mothers who gave birth to a live singleton baby, observed to 14 years of age. Family income was measured on 4 occasions from pregnancy to the 14-year follow-up. Child cognitive development was measured at the 14-year follow-up using the Raven's Standard Progressive Matrices and Wide Range Achievement Test.
Results: Poverty experienced at any stage of the child's development is associated with reduced cognitive outcomes. Exposure to poverty for a longer duration (birth to 14 years) is more detrimental to cognitive outcomes than experiencing poverty at only 1 period. For each additional exposure to poverty, the Raven's Standard Progressive Matrices scores declined by 2.19 units and the Wide Range Achievement Test scores declined by 1.74 units.
Conclusion: Children experiencing family poverty at any developmental stage in their early life course have reduced levels of cognitive development, with the frequency that poverty is experienced predicting the extent of reduced cognitive scores.