Maternal immigrant status and high birth weight: implications for childhood obesity

Childhood obesity, a growing epidemic, is associated with greater risk of several chronic diseases in adulthood. Children of immigrant mothers are at higher risk for obesity than children of non-immigrant mothers. High birth weight is the most important neonatal predictor of childhood obesity in the general population. To understand the etiology of obesity in children of immigrant mothers, we assessed the relation between maternal immigrant status and risk for high birth weight.

Data about all births in Michigan (N = 786,868) between 2000-2005 were collected. We used bivariate chi-square tests and multivariate logistic regression models to assess the relation between maternal immigrant status and risk for neonatal high birth weight.

The prevalence of high birth weight among non-immigrant mothers was 10.6%; the prevalence among immigrant mothers was 8.0% (P < .01). In multivariate regression models adjusted for maternal age, education, marital status, parity, and tobacco use, children of immigrant mothers had lower odds (odds ratio = 0.69, 95% confidence interval = 0.67-0.70) of high birth weight compared to those of non-immigrant mothers.

Although maternal immigrant status has been shown to be associated with greater childhood obesity, surprisingly, children of immigrant mothers have lower risk of high birth weight than children of non-immigrant mothers. This suggests that factors in early childhood, potentially cultural or behavioral factors, may play a disproportionately important role in the etiology of childhood obesity in children of immigrant vs non-immigrant mothers.