Both Restricted and Excessive Foetal Growth Increase the Odds of Failing Early Language Screening: A Register Study

Aim To investigate whether birth size for gestational age is associated with failure at language screening in early childhood. Methods This population‐based cohort study used linked national register data from Sweden. Children born between 2018 and 2023 who had undergone language screening at 2 years 4 months to 3 years 3 months of age were included ( n = 194 637; 94 051 females, 100 586 males). Logistic regression estimated associations between birth size for gestational age and screening failure, with children born appropriate for gestational age as the reference group, adjusting for sex, preterm birth, parental education, maternal smoking, and parental country of birth. Results Overall, 12% of children failed the language screening. Children born small for gestational age had higher odds of failure than appropriate for gestational age children (adjusted OR 1.42, 95% CI 1.30–1.54), as did children born large for gestational age (adjusted OR 1.24, 95% CI 1.15–1.33). Male sex, preterm birth, lower parental education, maternal smoking, and having two foreign‐born parents were each associated with screening failure. Conclusions Both restricted and excessive foetal growth were associated with increased likelihood of failing language screening, suggesting that deviations from typical foetal growth patterns may affect language development.