To examine the association between sleep and social-emotional development in two-year-old toddlers.
The study is part of a longitudinal cohort study, the Akershus Birth Cohort Study, which targeted all women giving birth at Akershus University Hospital in Norway. The current study is from the fourth round of the study, including 2014 women two years after delivery. The Brief Infant Sleep Questionnaire (BISQ) and the Ages and Stages Questionnaire: Social Emotional (ASQ:SE) were filled out by the mothers and were used to assess toddler sleep, and social-emotional development, respectively. Other domains of development (communication problems, gross motor problems, and fine motor problems) were assessed with the Ages and Stages Questionnaire (ASQ). Confirmatory factor analysis was conducted on the ASQ:SE, and logistic regression analyses were used to examine both crude associations between sleep variables and social-emotional problems, and adjusting for potential confounders.
The mean sleep duration of the toddlers was 12h and 27 min; the majority of the children (54%) had 1-2 awakenings per night, while 10% of the children had a sleep onset latency of more than 30 min. All sleep parameters, including short sleep duration, nocturnal awakenings and sleep onset problems, were significantly associated with social-emotional problems in a dose-response manner. For example, sleeping less than 11h per night was associated with a five-fold increase in the odds of social-emotional problems, compared to sleeping 13-14 h per night. Adjusting for potential confounders, including maternal age, maternal education, marital status, parity, gestational age, child birth-weight and other developmental problems, did not, or only slightly, attenuate the associations between any of the sleep variables and social-emotional problems.
Short sleep duration, nocturnal awakenings and sleep onset problems were all associated with higher odds of social-emotional problems, even after accounting for developmental problems and demographic factors. Thus, a broad assessment of sleep and social-emotional problems when toddlers present with either can be useful.