Exposure to acute ambient temperature extremes and neonatal intensive care unit admissions: A case-crossover study.

BACKGROUND: Extreme in utero temperatures have been associated with adverse birth outcomes, including preterm birth and low birthweight. However, there is limited evidence on associations with neonatal intensive care unit (NICU) admissions, which reflect a range of poor neonatal health outcomes. METHODS: This case-crossover study assesses the associations between ambient temperature changes during the week of delivery and risk of NICU admission. Data from the Consortium on Safe Labor (2002-2008) were linked to ambient temperature at hospital referral regions. Adjusted hazard ratios (HR) and 95 % confidence intervals (CI) estimated NICU admission risk with a 1 °C increase on each day of the week of delivery and of the average weekly temperature, adjusted for particulate matter ≤2.5 µm (PM2.5) and relative humidity. We also estimated associations with 1 °C increases and 1 °C decreases in temperatures during weeks of site-specific extreme heat (>90th and 95th percentiles) and cold (<5th and 10th percentiles), respectively. RESULTS: There were 27,188 NICU admissions with median (25th, 75th) temperature of 16.4 °C (5.8, 23.0) during the week before delivery. A 1 °C increase in temperature during the week of delivery was not associated with risk of NICU admission. However, analyses of extreme temperatures found that a 1 °C decrease in weekly average temperatures below the 10th and 5th percentiles was associated with 30 % (aHR = 1.30, 95 % CI 1.28, 1.31) and 47 % (aHR = 1.47, 95 % CI 1.45, 1.50) increased risk of NICU admissions, while a 1 °C increase in weekly average temperatures above the 90th and 95th percentiles was associated with more than two- (aHR = 2.29, 95 % CI 2.17, 2.42) and four-fold (aHR = 4.30, 95 % CI 3.68, 5.03) higher risk of NICU admission, respectively. CONCLUSIONS: Our study found temperature extremes in the week before delivery increased NICU admission risk, particularly during extreme heat, which may translate to more adverse neonatal outcomes as extreme temperatures persist.

Impacts of heat and wildfire on preterm birth.

BACKGROUND: Climate change continues to increase the frequency, intensity, and duration of heat events and wildfires, both of which are associated with adverse pregnancy outcomes. Few studies simultaneously evaluated exposures to these increasingly common exposures. OBJECTIVES: We investigated the relationship between exposure to heat and wildfire smoke and preterm birth (PTB). METHODS: In this time-stratified case-crossover study, participants consisted of 85,806 California singleton PTBs (20-36 gestational weeks) from May through October of 2015-2019. Birthing parent ZIP codes were linked to high-resolution daily weather, PM2.5 from wildfire smoke, and ambient air pollution data. Heat day was defined as a day with apparent temperature >98th percentile within each ZIP code and heat wave was defined as ≥2 consecutive heat days. Wildfire-smoke day was defined as a day with any exposure to wildfire-smoke PM2.5. Conditional logistic regression was used to calculate the odds ratio (OR) and 95% confidence intervals (CI) comparing exposures during a hazard period (lags 0-6) compared to control periods. Analyses were adjusted for relative humidity, fine particles, and ozone. RESULTS: Wildfire-smoke days were associated with 3.0% increased odds of PTB (ORlag0: 1.03, CI: 1.00-1.05). Compared with white participants, associations appeared stronger among Black, Hispanic, Asian, and American Indians/Alaskan Native participants. Heatwave days (ORlag2: 1.07, CI: 1.02-1.13) were positively associated with PTB, with stronger associations among those simultaneously exposed to wildfire smoke days (ORlag2: 1.19, CI: 1.11-1.27). Similar findings were observed for heat days and when other temperature metrics (e.g., maximum, minimum) were used. DISCUSSION: Heat and wildfire increased PTB risk with evidence of synergism. As the occurrence and co-occurrence of these events increase, exposure reduction among pregnant people is critical, especially among racial/ethnic minorities.

Gestational Diabetes and Subsequent Metabolic Dysfunction: An National Health and Nutrition Examination Survey Analysis (2011-2018).

Background: Gestational diabetes mellitus (GDM) complicates ∼10% of pregnancies, with the highest rates among Asian women. Evidence suggests that GDM is associated with an increased risk for future chronic health conditions, yet data for Asian women are sparse. We explored the association between prior GDM and metabolic dysfunction with nationally representative data to obtain Asian-specific estimates. Methods: For this cross-sectional study, data were drawn from the National Health and Nutrition Examination Survey for 7195 women with a prior pregnancy. GDM (yes/no) was defined using the question "During pregnancy, were you ever told by a doctor or other health professional that you had diabetes, sugar diabetes, or gestational diabetes?." Current metabolic dysfunction (yes/no) was based on having at least one of four indicators: systolic blood pressure (SBP, ≥130 mmHg), waist circumference (≥88 cm), high-density lipoprotein (HDL) cholesterol (<50 mg/dL), and glycosylated hemoglobin (HbA1c) (≥6.5%). Logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs) for the association between prior GDM and metabolic outcomes, overall and by race. Models included sampling weights and demographic and behavioral factors. Results: Overall, women with prior GDM had 46% greater odds of high waist circumference (OR: 1.5; 95% CI: 1.1-2.0) and 200% greater odds (OR: 3.0; 95% CI: 2.1-4.2) of high HbA1c. Prior GDM was not associated with high blood pressure or low HDL cholesterol. In race-specific analyses, prior GDM was associated with increased risk of elevated HbA1c among Asian (OR: 6.6; 95% CI: 2.5-17.2), Mexican American (OR: 3.0; 95% CI: 1.5-5.8), Black (OR: 3.0; 95% CI: 1.7-5.5), and White (OR: 2.6; 95% CI: 1.5-4.6) women. Prior GDM was associated with elevated SBP among Mexican American women and low HDL among Black women. Discussion: Prior GDM is associated with elevated HbA1c among all women, yet is a stronger predictor of elevated HbA1c among Asian women than other women. Race-specific associations between prior GDM and metabolic dysfunction were observed among Mexican American and Black women. Further research is warranted to understand the observed race/ethnic-specific associations.

Pesticide Take-Home Pathways, Storage, and Application Methods Among Hmong Farmers in Central Valley, California.

OBJECTIVE: Pesticide exposure via take-home pathways is a major health concern among farmers. However, little is known about the effects of pesticide take-home pathways on small-scale Hmong farmers in the Central Valley. This study explored factors that contribute to pesticide exposure via the take-home pathway among small-scale Hmong farmers in the Central Valley. METHODS: Detailed ethnographic observations of small-scale farms and corresponding homes were coupled with in-depth qualitative interviews with Hmong farmers to assess the extent of the pesticide take-home pathway. RESULTS: The study found daily challenges and numerous ways that pesticide particles may be introduced into farmers' homes. Given the paucity of research about Hmong farmers' pesticide take-home pathways, the study's findings advance the scholarship on pesticide exposures in the Hmong farmer community. CONCLUSION: This study advocates for more culturally and linguistically appropriate pesticide exposure training and educational programs tailored to Hmong farmers in the United States.

Testing the effectiveness of narrative messages using critical health communication.

BACKGROUND: Latinos suffer from health disparities associated with excessive consumption of sugar-sweetened beverages. This study aimed to test the effectiveness of messaging using critical health communication approaches and delivered by two narrative modalities (video and comic book) with similar content that aims to empower Latinos to advocate for social change and to make individual behavior change related to sugary beverage consumption. METHODS: Participants (N = 129 Mexican American women between 18 and 29 years) completed an online survey before and after exposure to an embedded stimulus. Participants were randomly assigned to a stimulus, a narrative message in video or comic book format, both developed using critical health communication approaches that focused on individual harms and social causes of sugary beverage consumption. RESULTS: Paired sample t-test results showed that both narrative messages increased intentions to reduce sugary beverage consumption (Video: P < 0.01; d = 0.43; Comic: P = 0.03; d = 0.28). Both groups also demonstrated significant improvements in sugary beverage-related media literacy (Video: P = 0.01, d = 0.34; Comic: P = 0.05, d = 0.25), public health literacy (Video: P = 0.05, d = 0.24; Comic: P = 0.01, d = 0.32), and empowerment to engage in sugary beverage-related community movements (Video: P = 0.003, d = 0.38; Comic: P = 0.034, d = 0.27). CONCLUSIONS: This study provides initial evidence indicating the effectiveness of narrative messages in two modalities using critical health communication for promoting individual behavioral intention and social activation in reducing sugary beverage consumption.

Measures of Racism and Discrimination in Preterm Birth Studies.

OBJECTIVE: Preterm birth (any birth at less than 37 weeks of gestation) disproportionally affects Black birthing people and is associated with adverse perinatal and fetal health outcomes. Racism increases the risk of preterm birth, but standardized measurement metrics are elusive. This narrative synthesis examines literature on measures of racial discrimination used in preterm birth research. DATA SOURCES: Six databases (CINAHL, Cochrane, EMBASE, PubMed [MEDLINE], Scopus, Web of Science) and ClinicalTrials.gov were searched. Search terms were categorized into three groups (racism terms, measurement terms, preterm birth terms) to identify original research articles that explored associations between racism and preterm birth. English-language, original research articles with U.S. populations were included. METHODS OF STUDY SELECTION: Studies were excluded if conducted in only White populations, if only paternal factors were included, or if only racial differences in preterm birth were described. Articles were independently reviewed by two blinded researchers for inclusion at every stage of screening and data extraction; a third reviewer resolved discrepancies. TABULATION, INTEGRATION, AND RESULTS: Sixty studies were included in the final analysis. Articles primarily included measures examining interpersonal forms of racism (n=17) through the Experiences of Discrimination and Everyday Discrimination scales, neighborhood composition (n=22) with the Neighborhood Deprivation Index and the Index of Concentration at the Extremes, policy-level racism (n=12) through institutions such as residential racial segregation or policy inequities, or multiple forms (n=9). CONCLUSION: Among studies, assessment methods and application of constructs varied. This heterogeneity poses significant challenges to understanding associations between racial discrimination and preterm birth and to describing potential etiologic pathways of preterm birth, which ultimately hinders development of effective intervention. Strategies to capture multilevel exposures to racism require the development and expansion of metrics that are culturally inclusive, empirically valid, and reliable among Black pregnant populations. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42022327484.

Beyond the infant in your arms: effects of climate change last for generations.

Climate change is the biggest global health threat of the 21st century. In addition to short-term reproductive health impacts, climate-related events will influence the risks of long-term and intergenerational mortality and morbidity for both birthing parents and offspring. As climate conditions continue to deteriorate in future generations, less healthy parents will give birth to less healthy offspring, who themselves will experience increased risk of reproductive outcomes. This intergenerational process causes a repeating cycle of poor parental preconception health, gestational complications, and poor offspring health, which leads to suboptimal preconception health among those offspring when they reach reproductive age. Because our ongoing efforts mostly focus on helping families achieve and maintain a healthy pregnancy, a critical need to think beyond the infant in our arms and consider the long-term implications of climate change exists. Such efforts may involve policy strengthening efforts to reduce emissions, further engaging health care providers as active advocates, ensuring equitable and sustainable mitigation and adaptable strategies, and conducting more research that yields actionable data to guide policy efforts, especially in regions and populations most affected by climate change.

Protocol: Effectiveness of message content and format on individual and collective efficacy in reducing the intention to consume sugar-sweetened beverages.

The strategic use of media is a common approach to promote health. A large body of evidence identifies specific features that increase message efficacy, including tailoring messages to the target audience and using a storytelling format. Yet most message testing research has focused on individual-level outcomes, ignoring the social and environmental determinants of health behaviors, which require collective action and political will to change. Grounded in an ecological approach to communication, we will carry out two double-blinded randomized experiments to test the relative effectiveness of message tailoring (culturally-tailored vs. standard) and format (narrative vs. didactic) to increase the intention to reduce individual sugar-sweetened beverage consumption, the understanding of social and commercial determinants of health, and the sense of empowerment among young adult Latinas. Based on power analyses (80% power at alpha = 0.05), we will randomize 438 participants to two groups (traditional standard infographic and culturally-tailored infographic) in the first study, and 662 participants to two groups (culturally-tailored infographic and culturally-tailored comic book) in the second study. All participants will be measured by a pre-treatment test and an immediate post-treatment test. We hypothesize that culturally-tailored comic book will be most effective, and traditional standard infographic will be least effective, on all levels of outcomes. This study will provide empirical evidence in communication strategies to help young Latinos or other racial/ethnic minority young people to pursue positive dietary behaviors that both benefit themselves and contribute to change of social norms.

The Changing Climate and Pregnancy Health.

PURPOSE OF REVIEW: Climate change is the biggest public health threat of the twenty-first century but its impact on the perinatal period has only recently received attention. This review summarizes recent literature regarding the impacts of climate change and related environmental disasters on pregnancy health and provides recommendations to inform future adaptation and mitigation efforts. RECENT FINDINGS: Accumulating evidence suggests that the changing climate affects pregnancy health directly via discrete environmental disasters (i.e., wildfire, extreme heat, hurricane, flood, and drought), and indirectly through changes in the natural and social environment. Although studies vary greatly in design, analytic methods, and assessment strategies, they generally converge to suggest that climate-related disasters are associated with increased risk of gestational complication, pregnancy loss, restricted fetal growth, low birthweight, preterm birth, and selected delivery/newborn complications. Window(s) of exposure with the highest sensitivity are not clear, but both acute and chronic exposures appear important. Furthermore, socioeconomically disadvantaged populations may be more vulnerable. Policy, clinical, and research strategies for adaptation and mitigation should be continued, strengthened, and expanded with cross-disciplinary efforts. Top priorities should include (a) reinforcing and expanding policies to further reduce emission, (b) increasing awareness and education resources for healthcare providers and the public, (c) facilitating access to quality population-based data in low-resource areas, and (d) research efforts to better understand mechanisms of effects, identify susceptible populations and windows of exposure, explore interactive impacts of multiple exposures, and develop novel methods to better quantify pregnancy health impacts.

Air pollution and preterm birth: A time-stratified case-crossover study in the San Joaquin Valley of California.

BACKGROUND: Air pollution is linked to preterm birth (PTB), but existing studies are primarily focused on chronic exposures, conducted in areas with moderate pollution, and/or subject to confounding. OBJECTIVES: We investigated short-term associations between two pollutants [particulate matter <2.5 microns (PM2.5 ) and ozone] and PTB, and estimated excess PTB cases potentially attributed to these pollutants. METHODS: This time-stratified case-crossover study includes 196,970 singleton pregnancies affected by PTB and early term birth from the San Joaquin Valley (SJV), California, USA (2007-2015). Daily ozone and PM2.5 concentrations were estimated by the SJV Air Pollution Control District and geospatially linked to maternal zip code. We used conditional logistic regression models to estimate the odds ratio (OR) and 95% confidence intervals (CI) for the associations between an interquartile range (IQR) increase in pollutants and very preterm (VPTB, 20-34 weeks), moderate preterm (MPTB, 34-36 weeks) and early term births (ETB, 37-38 weeks). We adjusted all models for co-pollutants and meteorological factors. RESULTS: During warm seasons (May-October), an IQR increase in ozone was associated with 9-11% increased odds of VPTB from lag 0 (ORlag0 1.09, 95% CI 1.04,1.16) to lag 7 (ORlag7 1.11, 95% CI 1.04,1.16). Findings were consistent for MPTB and ETB. Ozone was potentially responsible for an excess of 3-6 VPTBs, 7-9 PTBs and 24-42 ETBs per 1,000 singleton deliveries. During cold seasons (November-April), increased PM2.5 exposure was associated with 5-6% increased odds of VPTB beginning at lag 3 (ORlag3 1.06, 95% CI 1.02,1.11). PM2.5 was associated with an excess of 1-3 VPTBs, 0-3 MPTBs and 6-18 ETBs per 1,000 singleton deliveries. CONCLUSIONS: PM2.5 and ozone are associated with increased risk of VPTB, MPTB and ETB within one week of exposure and are potential contributors to the increasing PTB trend. More research is needed to further understand the role of air pollution on PTB risk.