Growth During Infancy After Extremely Preterm Birth: Associations with Later Neurodevelopmental and Health Outcomes

Abstract

To evaluate associations between changes in weight, length, and weight/length ratio during infancy and outcomes later in life among individuals born extremely preterm. Among participants in the Extremely Low Gestational Age Newborn (ELGAN) study, we measured weight and length at discharge from the neonatal intensive care unit (NICU) and at age 2years and evaluated neurocognitive, psychiatric, and health outcomes at age 10years and 15years. Using multivariable logistic regression, we estimated associations between gains in weight, length, and weight/length ratio z-scores between discharge and 2years and outcomes at 10 and 15years. High gain was defined as the top quintile of change; low gain, as the bottom quintile of change. High gains in weight and weight/length were associated with greater odds of obesity at 10years, but not at 15years. These associations were found only for females. High gain in length z-score was associated with lower odds of obesity at 15years. The only association found between high gains in growth measures and more favorable neurocognitive or psychiatric outcomes was between high gain in weight/length and lower odds of cognitive impairment at age 10years. During the 2years after NICU discharge, females born extremely preterm with high gains in weight/length or weight have greater odds of obesity at 10years, but not at 15years. Infants with high growth gains in the 2years after NICU discharge have neurocognitive and psychiatric outcomes in middle childhood and adolescence similar to those of infants with lower gains in weight and weight/length.