Association of Growth During Infancy With Neurodevelopment and Obesity in Children Born Very Preterm: The Environmental influences on Child Health Outcomes Cohort

Objective To evaluate associations between change in weight z-score after neonatal intensive care unit (NICU) discharge and neurodevelopmental outcomes and obesity at 12-48 months of age among individuals born very preterm. Study design This secondary analysis used data from infants born very preterm participating in the Environmental influences on Child Health Outcomes cohort (n=1400). Growth during infancy was calculated as change in weight z-score between NICU discharge and follow-up at a mean of 27 months of age. Very low weight gain was defined as a change in weight z-score<-1.67; very high weight gain was a change in weight z-score >1.67. Neurodevelopmental outcomes included the Bayley Scales of Infant and Toddler Development, Child Behavior Checklist 1.5-5 years, and Modified Checklist for Autism in Toddlers. Multivariable linear regression was used to estimate associations between increase in weight z-score and neurodevelopmental outcomes. Results Very low weight gain between NICU discharge and follow-up (experienced by 6.4% of participants) was associated with lower scores on cognitive (adjusted mean difference: -4.26; 95% confidence interval: -8.55, -0.04) and language (adjusted mean difference: -4.80; 95% confidence interval: -9.70, -0.11) assessments. Very high weight gain (experienced by 13.6% of participants) was associated with an increased obesity risk (adjusted relative risk: 6.20; 95% confidence interval: 3.99, 9.66) but not with neurodevelopmental outcomes. Conclusions Very high weight gain in the first 12-48 months after NICU discharge was associated with a higher risk of obesity at follow-up; very low weight gain was associated with lower scores on cognitive and language assessments.