Sleep problems during early and late infancy: Diverse impacts on child development trajectories across multiple domains

Objective: Child developmental rate holds predictive value for early-stage developmental trajectories, yet few studies explored how sleep problems during different infancy stages impact this rate. This study aims to investigate the correlation between sleep problems and child developmental trajectories. Methods: This study utilized a prospective national cohort of 5006 children in Taiwan. The developmental inventories covering motor, cognitive, language, and socioemotional domains were collected through questionnaire-based in-person home interviews conducted at 3, 12, 24, and 36 months. Sleep problems data, encompassing bedtime regularity, sleep duration, and sleep quality, were collected at 3 and 12 months. Child developmental rate was assessed by analyzing the slope of developmental ability estimates over a period of time. Results: Bedtime regularity and high-quality sleep at 3 and 12 months were found to be significantly associated with intercepts across all domains (estimate = −0.196∼0.233, p < 0.033). Children with high-quality sleep at 3 months showed enhanced developmental slopes in socioemotional domains (estimate = 0.032, p < 0.001). Atypical sleep duration at 3 and 12 months had differential detrimental association with child development in various domains (estimate = −0.108∼-0.016, p < 0.048). Conclusion: The relationship between sleep problems and child development exhibited variability based on the timing of exposure to these issues. Early exposure to low-quality sleep was significantly related to developmental functions and socioemotional developmental rate, potentially leading to increased developmental disparities as children age. Inadequate sleep duration in late infancy and excessive sleep duration in early infancy were both negatively associated with child development trajectories. Policymakers can use these findings to design targeted sleep programs for optimal child development.