  Objective. Sleep duration may vary inter-individually and intra-individually
over time. We aimed at both identifying night-sleep duration (NSD) trajectories
among preschoolers and studying associated factors. Methods. NSD were collected
within the French birth-cohort study EDEN at ages 2, 3 and 5-6 years through
parental questionnaires, and were used to model NSD trajectories among 1205
children. Familial socioeconomic factors, maternal sociodemographic, health and
lifestyle characteristics as well as child health, lifestyle, and sleep
characteristics at birth and/or at age 2 years were investigated in association
with NSD using multinomial logistic regressions. Results. Five distinct NSD
trajectories were identified: short (SS, <10h, 4.9%), medium-low (MLS, <11h,
47.8%), medium-high (MHS, $\approx$11h30, 37.2%), long (LS, $\ge$11h30, 4.5%)
and changing (CS, i.e. $\ge$11h30 then <11h, 5.6%) NSD trajectories.
Multivariable analyses showed in particular that, compared to the MHS
trajectory, factors associated with increased risk for belonging to SS
trajectory were male gender, first child, maternal age and working status,
night-waking, parental presence when falling asleep, television-viewing
duration and both the `Processed and fast foods' and the `Baby food' dietary
patterns at age 2 years. Factors positively associated with the CS trajectory
were maternal smoking, bottle-feeding at night and the `Processed and fast
foods' dietary pattern at age 2 years whereas child's activity and emotionality
scores at age 1 year were negatively associated. Conclusion. We identified
distinct NSD trajectories among preschoolers and associated early life factors.
Some of them may reflect less healthy lifestyle, providing cues for early
multi-behavioral prevention interventions
