Maternal Cultural Orientation and Child Growth in New Zealand Pacific Families

In New Zealand (NZ), children of Pacific heritage are generally born heavier and gain weight more quickly than non-Pacific children. Immigrants' health is commonly expected to converge with the host population through acculturation. The aim of this analysis was to examine whether mothers' acculturation is associated with less-rapid weight gain in NZ Pacific children, and whether this differs by mothers' nativity. In a birth cohort of 1249 children followed 2000-2011, birth weight and weight and standing height, measured at years 2, 4, 6, 9, and 11, were quantified as sex- and age-specific weight (weight-for-age; WFA) and BMI z-scores. Maternal acculturation (range, 11-54) was assessed at baseline and years 4, 6, and 11. In adjusted models using generalized estimating equations to account for repeated measures, maternal acculturation was not significantly associated with children's WFA or BMI z-scores overall. In stratified analyses, change in maternal acculturation score was inversely associated with WFA z-score change among children of NZ-born, but not immigrant, mothers (beta=-0.021; 95% confidence interval, -0.036 to -0.007; p=0.006; interaction, p=0.005). Our study provides the first evidence in a longitudinal sample that changes in maternal acculturation can influence children's growth, suggesting the importance of lifestyle or behavioral factors related to a mother's cultural orientation. Given the high risk of obesity and its related conditions in the NZ Pacific population, critical next steps are to identify mediating factors, as well as to understand the processes influencing growth among children of immigrant mothers.