Nighttime sleep-wake patterns and self-soothing from birth to one year of age: a longitudinal intervention study

Background: The objectives of this study were to: (1) describe the longitudinal development of sleep-wake patterns of solitary-sleeping infants from 1 to 12 months of age, (2) identify effects on sleep patterns and on self-soothing behaviors of introducing a novel sleep aid, and (3) identify predictive factors of self-soothing at 12 months using a transactional model as a guide. Methods: Eighty infants' nighttime sleep-wake patterns and associated variables were studied at 5 times across the first year of life using videosomnography and questionnaires. Results: Sleep-wake state developmental changes, as reported in investigations of infant sleep, were replicated, although a great deal of individual variability in the development of all sleep-related variables was noted. No major effects on sleep or on self-soothing behavior were evident from the introduction of the novel sleep aid. Three variables were identified as significant predictors of self-soothing at 12 months: decreasing amounts of time spent out of crib across the first year, high levels of quiet sleep at birth, and longer parental response times to infant awakenings at 3 months. Conclusions: These data lend preliminary support for the transactional model and suggest that infant and parental factors interact to influence the development of self-soothing.