Sleep characteristics and temperament in two years old children born preterm

Objectives Infants born preterm are at greater risk for different developmental conditions, such as language, learning and behavior disorders in respect to those born at term (Wolke, 2008). Prematurity also affect the development of the regulatory functions, in particular sleep (Kennaway, 2002). It is known that sleep in children is influenced not only by environmental factors, but also by intrinsic characteristics such as temperament (Sadeh, 2010). Few studies analyzed sleep in children born preterm and its relationship with the temperament. Therefore, our aims were to investigate in a group of two-years-old children born preterm: (1) the characteristics of sleep; (2) the temperamental dimensions; (3) the relationship between sleep pattern and temperament. Materials and methods The study included the mothers of 51 preterm (mean age 22 ± 5 months) and 57 term (mean age 21 ± 4 months) children. Mothers underwent a structured interview and filled out three questionnaires: the Italian temperament questionnaire (QUIT; Axia, 2002); Questionnaire on sleep quality (Q-sleep; Bruni) and the Brief Infant Sleep Questionnaire, Italian version (BISQ; Sadeh, 2004) that evaluates the sleep habits and patterns. To analyze the differences in the quality and sleep-related habits and in temperamental characteristics between the two groups of children chi-square tests were conducted on categorical data and a series of ANOVA on quantitative measures. Finally a correlational anaylsis has been carried out on sleep characteristics and temperament. Results Preterm children showed a higher degree of sleep problems [F (1,110) = 5.263, p <0.05] and of daytime sleepiness [F (1, 110) = 4.162, p <0.05] compared to those born at term. The temperament questionnaire analysis showed that preterm got lower scores in attention [F (1, 110) = 6.529, p <0.01] and higher scores in the negative emotionality [F (1, 110) = 6.970, p <0.01]. Finally, the correlation analysis between sleep and temperament in preterm showed that falling asleep difficulties are positively correlated with motor control and negative emotionality, and nocturnal sleep duration with the inhibition to the novelty. Conclusions Our study showed that preterm children had a high degree of problems related to sleep pattern and disturbances, and, a predominance of attention problems and negative emotionality.

This study demonstrated a link between infant sleep and temperament in preterm children.