Early growth patterns are associated with intelligence quotient scores in children born small-for-gestational age

Objective: To assess whether patterns of growth trajectory during infancy are associated with intelligence quotient (IQ) scores at 4 years of age in children born small-for-gestational age (SGA). Methods: Children in the Collaborative Perinatal Project born SGA were eligible for analysis. The primary outcome was the Stanford-Binet IQ score at 4 years of age. Growth patterns were defined based on changes in weight-for-age z-scores from birth to 4 months and 4 to 12 months of age and consisted of steady, early catch-up, late catch-up, constant catch-up, early catch-down, late catch-down, constant catch-down, early catch-up & late catch-down, and early catch-down & late catch-up. Multivariate linear regression was used to assess associations between patterns of growth and IQ. Results: We evaluated patterns of growth and IQ in 5640 children. Compared with children with steady growth, IQ scores were 2.9 [standard deviation (SD). = 0.54], 1.5 (SD = 0.63), and 2.2 (SD = 0.9) higher in children with early catch-up, early catch-up and later catch-down, and constant catch-up growth patterns, respectively, and 4.4 (SD = 1.4) and 3.9 (SD = 1.5) lower in children with early catch-down & late catch-up, and early catch-down growth patterns, respectively. Conclusions: Patterns in weight gain before 4 months of age were associated with differences in IQ scores at 4 years of age, with children with early catch-up having slightly higher IQ scores than children with steady growth and children with early catch-down having slightly lower IQ scores. These findings have implications for early infant nutrition in children born SGA.