Early features associated with the neurocognitive development at 36 months of age: the AuBE study.

Background: Few studies on the relations between sleep quantity and/or quality and cognition have been conducted among preschoolers from healthy general population. We aimed at identifying, among 36 months old children, early factors associated with intelligence quotient (IQ) estimated through the Weschler Preschool and Primary Scale Intelligence-III test and its indicators: Full-Scale-, Verbal- and Performance-IQs and their subscale scores.

Methods: We included 194 children from the French birth cohort AuBE with both available Weschler Preschool and Primary Scale Intelligence-III scores at three years and sleep data. Information was collected through self-questionnaires at birth, 6, 12, 18 and 24 months. A day/night sleep ratio was calculated.

Results: Mean scores were in normal ranges for Verbal, Performance, and Full-Scale IQs ?. In multivariate models, being a third-born or more child and watching television ≥1 h/day at 24 months were negatively associated with all IQ scores, whereas collective care arrangement was positively associated. Night waking at six months and frequent snoring at 18 months were negatively associated with Performance IQ, some subscales, and Full Scale IQ contrary to day/night sleep ratio at 12 months. No association was observed between early sleep characteristics and Verbal IQ.

Conclusion: We showed that early features including infant sleep characteristics influence IQ scores at 36 months old. Some of these may be accessible to prevention.