UC Irvine

Background: Hispanic mothers exhibit higher rates of adverse birth outcomes than non-Hispanic white mothers. Such disparities faced by Hispanic mothers may remain overlooked after decades of research in historical cohorts suggesting a paradoxical health advantage among Hispanic mothers despite their higher likelihood of low socioeconomic status than non-Hispanic white mothers. Although a paradoxical health advantage may exist in some places and times, recent national trends show increasing adverse birth outcomes among Hispanic mothers varying by maternal nativity and country of origin. Such increases may indicate a potential loss of the perinatal health advantage among Hispanic mothers in recent years. The extent to which place-based factors— including the social, political, and economic environments— explain differences by maternal nativity or country of origin has not received sufficient attention. The immigration enforcement landscape and residential demographics may illuminate contexts in which births to Hispanic mothers fare better or worse for either US-born or foreign-born Hispanic mothers. Objective: This dissertation advances the literature on birth outcomes among Hispanic mothers by (i.) incorporating a decomposition method to improve the current understanding of the differential role of immigration policy (ii). employing a unique sibling linked approach to examine the role of ethnic and immigrant density, and (iii). considering court deportation proceedings as a novel measure of immigration enforcement as it relates to perinatal health outcomes. Methods: I utilize birth certificate records from the National Center for Health Statistics (NCHS) for the US between 2015-2019 and from the California Department of Public Health for California between 2006-2022 to measure the health and sociodemographic characteristics of mothers and their infants. I use either county of residence or census tract to link these birth records to place-based measures of social, political, and economic environments. Chapter 2 uses a cross-sectional study design of national data to examine the association between low birthweight and preterm birth and place-based domains using linear regression and Fairlie decomposition methods. I use 4 place-based domains, including the social environment (e.g. percent Hispanic, percent foreign-born Hispanic), political environment (e.g. county’s entanglement with Immigration and Customs Enforcement (ICE)), economic environment (e.g. percent Hispanic below the federal poverty level, percent Hispanic receiving food stamps, percent unemployed), and geography (e.g. urban or rural) at the county level. Chapter 3 leverages a sibling study design in California to examine whether a Hispanic mother who moves to a census tract with higher ethnic density or immigrant density reduces the risk of low birthweight and preterm birth. Chapter 4 employs a multi-level model to examine the association between court deportation proceedings and low birthweight, macrosomia, small for gestational age, preterm birth, and birthweight percentile among subgroups of Hispanic mothers by maternal nativity and country of origin across California counties. Results: Findings (Chapter 2) show that a general prohibition to ICE in Hispanic communities (i.e., counties) appear to confer perinatal health benefits to Hispanic mothers. Also, moving to lower ethnic density and immigrant density neighborhoods increases the likelihood of low birthweight and preterm birth for US-born Hispanic mothers (Chapter 3). Lastly, an increasing rate of court deportation proceedings corresponds to an increased likelihood of preterm birth among both US-born and foreign-Hispanic mothers but not non-Hispanic white mothers (Chapter 4). Conclusions: Taken together, the findings of this dissertation suggest important roles of place-based characteristics on the birth outcomes of Hispanic mothers. The relative importance of these place-based factors, however, depends on maternal nativity and country of origin. Disaggregating Hispanic mothers by maternal nativity and country of origin provides a necessary avenue for understanding perinatal health among Hispanics. In addition, the ever-changing sociopolitical climate across place underscores the need to consider outcomes at the sub-state (e.g., county) level rather than aggregating to the state level.