Association of perinatal factors and school performance in primary school Chilean children

The associations between school performance and cognitive abilities with birth characteristics have mostly been studied without taking into consideration the effects of gestational age (GA). Our aim was to study the association between prenatal growth and cognitive function in term-born Chilean school children. A cohort of over 200,000 term-born fourth graders who took the regular national test for school performance was studied. Outcome parameters were language and mathematics test scores in relation to prenatal growth. A total of 256,040 subjects took the test and 220,940 were included in the final study sample. Prenatal growth was modestly, but significantly, associated with school performance. Adjusted β coefficients for 1 cm increase in birth length were 1.28 and 0.77 for mathematics and language, respectively; the corresponding values for 100 g increase in birth weight were 0.59 and 0.34, respectively. Increased GA was associated with lower test scores. Adjusted β coefficients for the birth measurements generally had a lower strength of association than those of socio-economic factors. However, the confounders most strongly associated with educational achievements were socio-economic factors, known to be associated with birth size. Lower socio-economic status is known to negatively influence both prenatal growth and cognitive function, supporting the overall importance of prenatal growth in relation to cognitive outcomes.