Birthweight Discordance on Reading and Externalizing Behavioral Outcomes

Achievement and behavioral problems in childhood have long-term consequences for better health and educational outcomes. Prenatal experiences have been linked with childhood outcomes, although there is some question as to the causative role of prenatal experiences on childhood cognitive and behavioral development and their related outcomes. Specifically, adverse outcomes related to birthweight have been associated with lower achievement outcomes and externalizing behaviors. Using a twin method with a sample of 396 pairs (N = 792), we examined if birthweight had a causal effect on childhood reading comprehension performance and parent-reported behavioral measures of executive function, ADHD, and conduct problems. Applying the co-twin control design within the counterfactual model of causality framework, the multilevel models determined whether causal mechanisms exist under differential exposure within and between twin pair associations Overall non-significant correlations were not found between individual birthweight and reading comprehension and externalizing behavioral outcomes of interest. Furthermore, in multilevel models, the birthweight exposure was not associated with any outcome, meaning it was not possible to evaluate any possible causal role of birthweight to reading or externalizing behavior.