Child development at age 5 years: The effects of maternal education, socioeconomic status and early-life growth examined prospectively in a lowresource setting

Background. Deeper insight into relationships between social factors and early childhood growth and development is required, particularly in low-resource settings. Objectives. To determine (i) associations between early linear growth and child development at 5 years; and (ii) whether early childhood growth mediates relationships between maternal education, household socioeconomic status (SES) and subsequent child development. Methods. This study used data from the Birth to Twenty Plus study, a longitudinal South African birth cohort study. The study sample comprised 636 participants with complete data at all relevant time points for the analysis. Household SES and maternal education were measured during pregnancy and the first two years of life, and growth between birth and 4 years of age. Child development was assessed using the Revised Denver Pre-screening Developmental Questionnaire (R-DPDQ). Multivariable regression analyses were used to investigate the association between SES, maternal education, growth and child development, and structural equation modelling was used to analyse the mediation of growth. Results. In both sexes, higher birthweight and household SES were associated with higher R-DPDQ scores. Increased relative linear growth, particularly between 0 and 2 years, was associated with higher R-DPDQ scores among boys (β=0.82; 95% confidence interval (CI): 0.27 - 1.37) at age 5. Growth status but not SES mediated the association between maternal education and R-DPDQ scores. Conclusion. Child development at 5 years was independently associated with SES and birthweight. The negative effects of lower maternal education on child development was attenuated by better growth.