Analysis of State-Level Immigrant Policies and Preterm Births by Race/Ethnicity Among Women Born in the US and Women Born Outside the US.

Importance Criminalizing immigrant policies, a form of structural racism, are associated with preterm birth; however, to date, few population studies have examined this association by race and nativity status or examined the association of inclusive immigrant policies with preterm birth. Objective To assess the extent to which variation in preterm birth by race/ethnicity and nativity status is associated with state-level criminalizing vs inclusive immigrant policies. Design, Setting, and Participants This retrospective, cross-sectional study analyzed birth record data from all 50 states and the District of Columbia in 2018, as well as state-level indicators of inclusive and criminalizing immigrant policies. White, Black, Asian, and Latina women who had singleton births were included in the study. Statistical analysis was performed from June 1, 2020, to February 5, 2021. Two continuous variables were created to capture the number of criminalizing vs inclusive immigrant policies in effect as of 2017 in each state. Main Outcomes and Measures The main outcome measure was preterm birth (<37 weeks' gestation). Results Among the 3 455 514 live births that occurred in 2018, 10.0% were preterm, and 23.2% were to mothers born outside the US. Overall, for women born outside the US, each additional state-level inclusive policy was associated with a 2% decrease in preterm birth (adjusted odds ratio [aOR], 0.98 [95% CI, 0.96-1.00]); there were no significant associations between inclusive policies and preterm birth among women born in the US. In models examining the combined associations of criminalizing and inclusive immigrant policies with preterm birth, each additional criminalizing policy was associated with a 5% increase in preterm birth among Black women born outside the US (aOR, 1.05 [95% CI, 1.00-1.10]). Each additional inclusive immigrant policy was associated with a lower likelihood of preterm birth for Asian women born in the US (aOR, 0.95 [95% CI, 0.93-0.98]) and White women born outside the US (aOR, 0.97 [95% CI, 0.95-0.99]). No significant associations were found among other groups. Conclusions and Relevance This study suggests that criminalizing immigrant policies are associated with an increase in preterm birth specifically for Black women born outside the US. Inclusive immigrant policies are associated with a decrease in preterm birth for immigrants overall, Asian women born in the US, and White women born outside the US. No associations were found between criminalizing or inclusive immigrant policies and preterm birth among Latina women.