Pregnancy-related weight among immigrant and US-born mothers: The role of nativity, maternal duration of residence, and age at arrival

Objectives: The goals of this study were to examine the associations between nativity and pregnancy-related weight and to assess the associations between maternal duration of residence and age at arrival in the United States on pregnancy-related weight among immigrants. Methods: Using logistic regression and data from the Early Childhood Longitudinal Study–Birth Cohort, we assessed differences in preconception weight and gestational weight gain between US-born and immigrant women (N = 7000). We then analyzed differences in both outcomes by duration of residence among immigrants (n = 1850) and examined whether the identified relationships varied by age at arrival in the United States. Results: Compared to US-born mothers, immigrants were less likely to be classified as obese prior to pregnancy (odds ratio 0.435, 95% confidence interval, 0.321–0.590) or experience excessive gestational weight gain (odds ratio 0.757, 95% confidence interval, 0.614–0.978). Among the immigrant sub-sample, living in the United States for 10–15 years (odds ratio 2.737, 95% confidence interval, 1.459–5.134) or 16+ years was positively associated with both preconception obesity (odds ratio 2.918, 95% confidence interval, 1.322–6.439) and excessive gestational weight gain (odds ratio 1.683, 95% confidence interval, 1.012–2.797, 16+ years only). There was some evidence that the duration of residence was positively associated with preconception obesity, but only among women who had moved to the United States at age 18 years and older. Conclusion: In sum, while immigrants are less likely than US-born mothers to experience preconception obesity or excessive gestational weight gain, these outcomes vary among the former group by duration of US residence.