Affiliation:
1. Grupo de Bioestadística Aplicada, Facultad de Ciencias Exactas y Naturales Universidad de Buenos Aires and CONICET Buenos Aires Argentina
2. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos, CONICET, Hospital “El Cruce” Universidad Arturo Jauretche Florencio Varela Argentina
Abstract
AbstractObjectivesTo investigate the association between the anthropometric status at birth and brain and bone growth during the first year of life. According to the brain‐sparing hypothesis, we expect catch‐up to be faster in head circumference (HC) than in body length.MethodsThis is a longitudinal design that included Argentinian infants under 12 months of age with at least three anthropometric records. We classified study participants into four growth status categories according to z‐scores for HC (HCZ) and length (LAZ) at birth, with z‐score = −2 as a threshold. We used the Count model to describe growth trajectories in HC and length in the first year of life according to the growth status at birth. Recovery indicator for HC and length was taken as the time until the predicted growth trajectory surpassed the threshold curve predicted by z‐score = −2 for age.ResultsGrowth models included 3399 infants. There were significant differences in the growth parameters between groups in all cases (p < 0.05). Within the group with a low HCZ and a low LAZ at birth, HC recovery was faster than length. In the case of a low z‐score for only one of the variables, newborns with a low HCZ recovered faster than individuals born with a low LAZ.ConclusionsThe postnatal growth pattern in HC and length is associated with the growth status of HC and length at birth. As we hypothesized, the fastest postnatal recovery occurs for HC in cases of intrauterine delayed growth.