Objectives: To identify the prevalence and risk factors for childhood overweight and obesity (OWO) at 3-year corrected age in children born <1500 g <29 weeks gestation.
Study design: A multicentre retrospective cohort study for preterm infants admitted to neonatal intensive care units between 2001 and 2014.
Results: Data were available for 911 (89.4%) of the 1019 infants who met the inclusion criteria. Of them, 22 (2.4%) had OWO. There were no associations between OWO and being small for gestational age (RR = 1.3, 95% confidence interval (CI): 0.3-5.4) or weight <10th percentile at 36 weeks (RR = 1.1, 95% CI: 0.4-2.8). OWO was associated with low maternal education (RR = 7.4, 95% CI: 2.1-26), maternal diabetes (RR = 5.2, 95% CI: 1.9-15) and neonatal brain injury (RR = 4.9, 95% CI: 1.8-14). Adjusting for concurrent child weight at 3 years of age resulted in an overadjustment bias.
Conclusion: Small size at birth or at 36 weeks gestation in extremely preterm infants is not associated with increased risk of early childhood overgrowth or obesity.
Clinical trial registration: NCT03064022.
© 2021. The Author(s), under exclusive licence to Springer Nature America, Inc.