Elaine Symanski

Background: Non-Hispanic Black women have almost double the risk of preterm birth compared with non-Hispanic White women in the United States, and the disparity is not fully explained by sociodemographic factors, health behaviors, or medical factors. Thus, it is critical to look beyond these “traditional” risk factors and evaluate contributions from psychosocial stressors, chemical exposures, and features of residential environments where pregnant women live. Methods: This study was conducted among 1,847 Black and White women recruited at the time of delivery between 2021 and 2023 in greater Houston, Texas to examine the contribution of individual- and neighborhood-level factors to the Black/White disparity in preterm birth using two-fold Blinder–Oaxaca decomposition. We evaluated the contribution from variables within the following domains: sociodemographics; perinatal history; comorbidities and health behaviors; chemical exposures; social factors; and neighborhood characteristics. We present the results as percent contributions to the disparity for each covariate and by domain. Results: With a 6.6% higher prevalence of preterm birth among Black mothers compared with White mothers, variables included in our decomposition analysis explained 63.0% of the preterm birth disparity, with perinatal history explaining the highest proportion (36.3%), followed by neighborhood characteristics (32.8%). Individual variables with the highest contributions included residing in a more racially minoritized and economically disadvantaged neighborhood (19.2%) and having a previous pregnancy complication (18.5%), a hypertensive disorder in the index pregnancy (16.7%), or chronic hypertension before pregnancy (16.8%). Conclusion: Our study underscores the importance of perinatal history and neighborhood factors in explaining disparities in preterm birth, which should be further explored in other populations.

Preterm birth (PTB) remains a leading cause of neonatal morbidity and mortality and disproportionately affects Black women in the United States. While racial disparities in PTB are well documented, the molecular pathways underlying these differences remain incompletely understood. Extracellular vesicles (EVs) are circulating lipid-bound particles that carry coding and non-coding RNAs reflecting cellular stress states and may serve as integrative molecular indicators of pregnancy biology. In this hypothesis-generating pilot study, EVs were isolated from maternal plasma collected at delivery from non-Hispanic Black and non-Hispanic White women with preterm and full-term births. EV concentration and size were assessed, and EV-associated mRNA and miRNA cargo were profiled by next-generation sequencing (n = 5 per group), enabling differential expression and pathway enrichment analyses stratified by gestational outcome. EV concentrations were significantly elevated in PTB compared with full-term deliveries (p < 0.0001), with a greater increase among Black participants. Analysis of EV-associated mRNA transcripts identified a shared signature enriched for platelet activation and coagulation pathways across racial groups. Race-stratified analyses revealed distinct EV miRNA profiles in PTB, with enrichment of cytokine-mediated signaling pathways among Black participants and apoptosis-related pathways among White participants, while a subset of miRNAs differed by race independent of gestational outcome. These findings support EV profiling as a framework to investigate biological pathways contributing to PTB disparities.

Background: While there is growing evidence of the negative impact of neighborhood segregation on maternal and infant health, the evidence for stillbirth is limited. Methods: A retrospective cohort study of live births and stillbirths for 2007–2020 was conducted in greater Houston, TX, to examine the associations of racialized economic segregation, assessed using the Index of Concentrations at the Extremes (ICE), with stillbirth. Here, ICE contrasted census tract-level racial and economic privilege with disadvantage (i.e., high-income non-Hispanic White persons vs. low-income Persons of Color). Additionally, Oaxaca-Blinder decomposition methods were applied to examine the degree to which segregation and maternal risk factors explained observed racial disparities in stillbirth. Results: The prevalence of stillbirth was highest among non-Hispanic Black mothers (9.1/1000) compared with Hispanic mothers (4.7/1000), non-Hispanic White mothers (3.8/1000), and mothers whose race or ethnicity was unknown or classified as other (3.7/1000). In models adjusted for age, pre-pregnancy body mass index (BMI), smoking during pregnancy, and education, odds of stillbirth were reduced for non-Hispanic White mothers living in the most privileged neighborhoods (OR = 0.82, 95% CI 0.60, 1.12 for ICE tertile 3 vs. ICE tertile 1). In contrast, residing in more privileged neighborhoods did not confer the same benefit for mothers of other racial and ethnic groups. Based on the decomposition analysis, maternal age, education, pre-pregnancy BMI, smoking, and ICE explained 21.2% of the disparity in stillbirth between non-Hispanic Black and non-Hispanic White mothers; of which, having a high school education or less (12.3%), living in the most privileged neighborhoods (9.7%), and being obese (7.2%) contributed the most. Conclusions: Neighborhood privilege appears to confer benefits for White mothers but not for non-White mothers, potentially due to experiences of racial discrimination that offset economic advantages. While racialized economic segregation contributed modestly to Black-White disparities in stillbirth, much of the disparity remains unexplained by the factors examined. Future research should explore additional individual- and neighborhood-level contributors to these disparities while addressing inequities to reduce stillbirth risks across all populations.

Introduction: The Maternal and Infant Environmental Health Riskscape (MIEHR) Center was established to address the interplay among chemical and non-chemical stressors in the biological, physical, social, and built environments that disproportionately impact perinatal health among Black pregnant people in a large and diverse urban area with documented disparities in the U.S.Methods: The MIEHR cohort is recruiting non-Hispanic Black and non-Hispanic white pregnant people who deliver their infants at major obstetric hospitals in Houston, Texas. At enrollment, all participants are asked to provide urine samples for chemical [metals, cotinine, and polycyclic aromatic hydrocarbons (PAHs)] analyses and blood samples. A subset of the cohort is asked to provide oral and vaginal swabs, and fecal samples. Questionnaire and electronic health record data gather information about residential address history during pregnancy, pregnancy history and prenatal care, sociodemographic and lifestyle factors, experiences of discrimination and stress, and sources of social support. Using information on where a participant lived during their pregnancy, features of their neighborhood environment are characterized. We provide summaries of key individual- and neighborhood-level features of the entire cohort, as well as for Black and white participants separately.Results: Between April 2021 and February 2023, 1,244 pregnant people were recruited. Nearly all participants provided urine samples and slightly less than half provided blood samples. PAH exposure patterns as assessed on 47% of participants thus far showed varying levels depending on metabolite as compared to previous studies. Additionally, analyses suggest differences between Black and white pregnant people in experiences of discrimination, stress, and levels of social support, as well as in neighborhood characteristics.Discussion: Our findings to date highlight racial differences in experiences of discrimination, stress, and levels of support, as well as neighborhood characteristics. Recruitment of the cohort is ongoing and additional neighborhood metrics are being constructed. Biospecimens will be analyzed for metals and PAH metabolites (urine samples), miRNAs (plasma samples) and the microbiome (oral swabs). Once enrollment ends, formal assessments are planned to elucidate individual- and neighborhood-level features in the environmental riskscape that contribute to Black-White disparities in perinatal health.

Background: Children living in environmental justice (EJ) neighborhoods may be vulnerable to metal exposure from industrial facilities that are located near their homes. Methods: Working with community partners, we held 20 recruitment events and invited children aged 5–12 and their parents living in EJ communities in Houston to participate in an environmental health study. Parents completed a questionnaire about their child's diet and behaviors and urine samples were collected from children to evaluate their metal exposure. Results: During a 4-month period, we recruited 52 out of 67 (78%) eligible parent/child dyads with 96% of children providing urine samples and 90% of questionnaires complete except for data on children's height and weight. While urinary metal concentrations in our study population were generally similar compared with children aged 6–11 years in the 2015–2016 National Health and Nutrition Examination Survey, we observed higher levels among children who frequently ate Mexican candy, rice, or red meat, spent more time outdoors, played with cosmetics, had metal piercings, or lived in a home with smokers or where pesticides were used. Discussion: Our study was successful in recruiting children in EJ communities for the purpose of assessing urinary metal exposure and obtaining questionnaire data from parents to examine the potential sources of exposure. Except for chromium and cobalt, 14 metals were detected in more than half of children's urine samples. We identified potential key determinants of exposure in this population that should be further examined. Conclusion: Findings point to the need for adequately powered studies among potentially vulnerable children living in EJ communities to profile metal exposures and identify important sources of these exposures.

Exposures to environmental contaminants can be influenced by social determinants of health. As a result, persons living in socially disadvantaged communities may experience disproportionate health risks from environmental exposures. Mixed methods research can be used to understand community-level and individual-level exposures to chemical and nonchemical stressors contributing to environmental health disparities. Furthermore, community-based participatory research (CBPR) approaches can lead to more effective interventions. We applied mixed methods to identify environmental health perceptions and needs among metal recyclers and residents living in disadvantaged neighborhoods near metal recycling facilities in Houston, Texas, in a CBPR study, Metal Air Pollution Partnership Solutions (MAPPS). Informed by what we learned and our previous findings from cancer and noncancer risk assessments of metal air pollution in these neighborhoods, we developed an action plan to lower metal aerosol emissions from metal recycling facilities and enhance community capacity to address environmental health risks. Key informant interviews, focus groups, and community surveys were used to identify environmental health concerns of residents. A diverse group from academia, an environmental justice advocacy group, the community, the metal recycling industry, and the local health department collaborated and translated these findings, along with results from our prior risk assessments, to inform a multifaceted public health action plan. An evidence-based approach was used to develop and implement neighborhood-specific action plans. Plans included a voluntary framework of technical and administrative controls to reduce metal emissions in the metal recycling facilities, direct lines of communication among residents, metal recyclers, and local health department officials, and environmental health leadership training. Using a CBPR approach, health risk assessment findings based on outdoor air monitoring campaigns and community survey results informed a multipronged environmental health action plan to mitigate health risks associated with metal air pollution. https://doi.org/10.1289/EHP11405