Critical examination of relationships between early growth and childhood overweight in extremely preterm infants.

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.