The Relationship Between Preterm and Small for Gestational Age on Child Cognition During School-Age Years

Objectives: Children born preterm and/or small for gestational age (SGA) have a high susceptibility to neurological impairments that may affect cognitive and learning outcomes during school age and beyond. Yet, limited evidence exists for these high-risk birth phenotypes in low and middle-income countries where most occur with different etiology and socio-biology. This paper examined the deficits in cognitive function and academic achievement during the school age years in children born preterm or SGA compared to term adequate for gestational age (AGA) in rural Vietnam. Methods: Children born to women in a randomized controlled trial of preconception micronutrient supplementation in Vietnam were classified into 3 groups: preterm AGA (n = 138), full-term SGA (n = 169) and full-term AGA (n= 1134). Child cognitive abilities were assessed using the Wechsler Intelligence Scale for Children to measure four domains (verbal comprehension -VCI, perceptual reasoning -PRI, working memory -WMI, and processing speed Index scores - PSI) and full-scale intelligence quotient (FSIQ) at 6-7y and 10-11y. Child academic achievement was assessed using a math and language test. We used ANOVA and multiple regression models to examine the differences in cognitive function and academic achievement at 6-7y and 10-11y by birth. Results: Compared to those born term AGA, SGA children had lower scores in various areas of cognitive ability both at 6-7y (-2.3 for VCI, -3.7 for PRI, -2.1 for PSI and 2.9 for FSIQ) and 10-11y (-3.7 for VCI, -3.5 for PRI, -2.7 for WMI, -1.9 PSI and -3.9 for FSIQ). SGA children also had poorer academic achievement with 5.3 and 2.5 points lower in language and math, respectively. Adjustments for maternal factors, home environment and child feeding attenuated the associations, but the differences in PRI, FSIQ and language at 10-11y remained significant. There were no differences in cognitive function and academic achievement between preterm and AGA children. Conclusions: Our findings highlight the enduring impact of birth phenotype on cognitive functioning and academic achievement during the school years, despite adjustments for child feeding, maternal education and family environment. Addressing the educational needs of these children during school age is crucial. Funding Sources: The Nestle Foundation, the Mathile Institute, the Micronutrient Initiative.