To examine the association between individuallevel and state-level migration status in the United States (US) and the risk of preterm and low birth weight infants among Mexican-origin women. We performed secondary analysis of the 2003 US birth certificate data for 641,474 infants born to Mexican-origin Latina women. The dependent variables were prematurity and low birth weight. The primary independent variables were individual- (maternal) and state-level migration status. Logistic regression analysis estimated the relationship between maternal and state-level migration status, maternal and infant factors, and the risk of prematurity and low birth weight. Women who were born in Mexico had less education and use of prenatal care than US-born, Mexicanorigin women but also fewer preterm or low birth weight infants. After adjusting for maternal and infant characteristics, women who were born and resided in Mexico at delivery were 37-64 % less likely to deliver preterm or low birth weight infants, and women who were born in Mexico and resided in the US had a 20-21 % lower risk as compared to women who were born and resided in the same US state. Women who delivered in states with a higher proportion of Mexican-origin mothers were slightly more likely to deliver a preterm infant and slightly less likely to give birth to a low birth weight infant. These findings support the perinatal advantage of Mexican-born women and provide evidence that both individual- as well as statelevel migration factors influence perinatal outcomes.

Preterm infant Mexican-origin Low birth weight

multicenter study prenatal care Maternal Age clinical trial risk Follow-Up Studies follow up human risk assessment Odds Ratio statistics and numerical data Confidence Intervals comparative study Databases, Factual factual database Infant, Premature ethnology procedures Confidence interval Young Adult United States Humans Infant, Newborn female Infant newborn pregnancy Infant, Low Birth Weight Mexican American Retrospective Studies low birth weight pregnancy outcome adult migration prematurity Infant Mortality Transients and Migrants retrospective study gestational age Mexican Americans