The differential effect of foreign-born status on low birth weight by race/ethnicity and education.

OBJECTIVES This article investigates whether foreign-born status confers a protective effect against low birth weight (LBW) and whether this protective effect varies across racial/ethnic groups and by socioeconomic status (ie, education) within various racial/ethnic groups. METHODS Logistic regression analyses of the Detail Natality Data, 1998 (n = 2,436,890), were used to examine differentials in LBW by nativity across racial/ethnic groups and by education level. RESULTS Although foreign-born status does not protect against LBW among white women (95% confidence interval [CI]: 0.96, 1.03) and it increases the risk among Asian women by 24% (95% CI: 1.13, 1.36), it reduces the risk by approximately 25% among black women (95% CI: 0.72, 0.78) and by approximately 19% among Hispanic women (95% CI: 0.78, 0.84). By educational attainment, for whites, blacks, and Hispanics the protective effect of foreign-born status is stronger among women with low education (ie, 0-11 years) than among women with more education. The educational gradient in LBW is less pronounced among foreign-born white, black, and Hispanic women than among their US-born counterparts. CONCLUSIONS Foreign-born status is associated with LBW. The direction and strength of this association varies across racial/ethnic groups, and within those groups it varies by educational level. Future research may test hypotheses regarding the mechanisms underlying these variations in LBW, including health selection of immigrants, cultural factors, social support, and social environment.