Abstract
AIM: Sleep is essential for infant development. We assessed the prevalence of sleep problems in infants at 6, 12 and 24 months, investigated the relationship between infants' sleep problems and development, and determined to what extent sleep problems at 6 months were related to changes in the developmental course. METHODS: Infant sleep problems were measured by a parent-reported sleep questionnaire. The Ages and Stages Questionnaires were used to measure developmental skills in a sample of 1555 infants recruited from 9 well-baby clinics in Norway. ASQ scores were compared between infants with and without sleep problems by using two-sample t-tests. The relationship between infant sleep problems at 6 months and changes in Ages and Stages Questionnaires scores over time was investigated using linear mixed-effects models. RESULTS: The prevalence of infant sleep problems were 14.6% at 6 months, 7.4% at 12 months and 3.3% at 24 months. There was no clear evidence of differences in ASQ or ASQ:SE scores by sleep problems from 6 to 24 months, but communication and problem-solving scores for infants with sleep problems increased faster. CONCLUSION: Prevalence of sleep problems decreased with age. There was no clear evidence of early sleep disturbance and later development problems.