Lifestyle behaviours in children born extremely preterm at 2 years: a comparison to a Dutch reference population

Children born extremely preterm (EP, < 28 weeks gestation) are at increased risk of lifestyle-related morbidities. This study characterized parent-reported lifestyle behaviours in EP-born children at 2 years' corrected age (CA) and compared them with a Dutch reference population. In a multicentre prospective cohort study, parents completed the FLY-Kids lifestyle screening questionnaire (2 years' CA), which assessed parental satisfaction and adherence to age-specific recommendations for diet, eating habits, physical activity, screen time and sleep. Outcomes were compared with a Dutch reference sample of 2-year-olds, and associations were examined using linear regression. Of 269 eligible children, 239 parents responded. After exclusions (n = 63), 176 children (74%) were enrolled, of whom 115 (65%) completed the questionnaire (14 twin-pairs). Compared with the Dutch reference population (n = 73), lifestyle recommendations were more often unmet in EP children (mean = 3.92 vs. 3.29 items, p = 0.01). Interestingly, a larger proportion of EP children exceeded the recommended sleep duration (≥ 14 h) (p < 0.001), while other lifestyle items were similar. In both populations, > 30% of children failed to meet the recommendations for seven out of nine items. Higher socioeconomic status (p = 0.016) and having at least one foreign-born parent (p = 0.034) were associated with lower parental satisfaction. Bronchopulmonary dysplasia diagnosis was associated with greater adherence to recommendations (p < 0.001), while being underweight (p = 0.029) associated with more unmet recommendations.

Despite longer sleep duration, lifestyle behaviours in EP children at 2 years' CA largely resemble those of the general population. However, poor adherence to lifestyle recommendations highlight the need for targeted interventions to reduce lifestyle-associated morbidities in EP children.

• Healthy lifestyle behaviours in early childhood are essential for long-term health outcomes. • Extremely preterm (EP)-born children have an elevated risk of lifestyle-related morbidities. However, knowledge on lifestyle behaviours during toddlerhood in this population remains limited.

• Characterization of lifestyle behaviours in this specific group of EP-born children at 2 years' corrected age offers novel insights. • Except for longer sleep duration, lifestyle behaviours largely resemble the general population. However, over 30% of children in both EP and term populations fail to meet recommendations for 7 of the 9 lifestyle items included in the FLY-Kids tool.