Birth weight and school absences and attainment: a longitudinal linked cohort study of compulsory schooling in England

Abstract

Objective: To explore how birth weight and size-for-gestation may contribute to school absences and educational attainment and whether there are different associations across sex and income groups.

Design: Longitudinal linked cohort study.

Methods: Data were drawn from the Millennium Cohort Study, a nationally representative cohort of children born in 2000-2001; percentage of authorised and unauthorised absences from Year 1 to Year 11, and Key Stage test scores at ages 7, 11 and 16 in English and Maths were linked from the National Pupil Database. Birth outcomes and covariates were derived from the 9-month survey, and linear regressions with complex survey weights were fitted.

Results: Being born small-for-gestational-age (vs average-for-gestational-age) was associated with an increase of 0.47%, 0.55% and 0.40% in authorised absences in Years 1, 3 and 4 (n=6659) and with a reduction of 0.16-0.26 SD in all English and Maths test scores (n=6204). Similar associations were found for birth weight. After adjusting for prior test scores, English (b=0.07) and Maths (b=0.05) performance at age 11 remained associated with birth weight. Socioeconomic status modified the associations: there were larger disparities in test scores among higher-income families, suggesting that higher income did not compensate for being born small-for-gestational-age.

Conclusion: Children born smaller missed slightly more classes (~1 day per year) during primary school and had lower English and Maths performance across compulsory education. Exploring specific health conditions and understanding how education and health systems can work together to support children may help to reduce the burden.

Keywords: Child Health; Epidemiology; Infant Development.

Figure 1. Percentage of missed sessions in Years 1–11 by (a) birth weight and (b) SGA. Key stage examinations took place in grey-shaded academic years; birth weight was categorised for this plot into low (<2.5 kg), average (2.5–3.9 kg) and large groups (≥4 kg), n=6659. SGA, small-for-gestational-age.

Figure 2. Associations between (a) birth weight, (b) small-for-gestational-age (compared with average-for-gestational-age) and percentage of missed sessions in Years 1–11. Key stage examinations took place in grey-shaded academic years. Linear regressions with complex survey weights were fitted separately for authorised and unauthorised absences; in addition to unadjusted associations, plots present estimates controlled for sex, month of birth, ethnic groups, partnership status, maternal age at birth, maternal smoking, number of siblings, household tenure, highest household education attainment, household income and area-level income deprivation, n=6659.

Figure 3. Predicted values of standardised test scores for pupils with average and small-for-gestational-age birth weights across different household income quintiles (Q1–Lowest; Q2; Q3; Q4 and Q5–Highest). Linear regressions with complex survey weights were fitted, and models controlled for sex, month of birth, ethnic groups, partnership status, maternal age at birth, maternal smoking, number of siblings, household tenure, highest household education attainment, and area-level income deprivation. n=6204. KS, Key Stage; SGA, small-for-gestational-age.