Article

Fine Particulate Matter and Risk of Preterm Birth in Connecticut in 2000-2006: A Longitudinal Study

American journal of epidemiology (Impact Factor: 5.23). 09/2013; 179(1). DOI: 10.1093/aje/kwt216
Source: PubMed

ABSTRACT

Several studies have examined associations between particulate matter with aerodynamic diameter of 2.5 µm or less (PM2.5) and preterm birth, but it is uncertain whether results were affected by individual predispositions (e.g., genetic factors,
social conditions) that might vary considerably between women. We tested the hypothesis that a woman is at greater risk of
preterm delivery when she has had elevated exposure to ambient PM2.5 during a pregnancy than when she has not by comparing pregnancies in the same woman. From 271,204 births, we selected 29,175
women who had vaginal singleton livebirths at least twice in Connecticut in 2000–2006 (n = 61,688 births). Analyses matched pregnancies to the same woman. Adjusted odds ratios per interquartile range (2.33-µg/m3) increase in PM2.5 in the first trimester, second trimester, third trimester, and whole pregnancy were 1.07 (95% confidence interval (CI): 1.00,
1.15), 0.96 (95% CI: 0.90, 1.03), 1.03 (95% CI: 0.97, 1.08), and 1.13 (95% CI: 1.01, 1.28), respectively. Among Hispanic women,
the odds ratio per interquartile range increase in whole-pregnancy exposure was 1.31 (95% CI: 1.00, 1.73). Pregnancies with
elevated PM2.5 exposure were more likely to result in preterm birth than were other pregnancies to the same woman at lower exposure. Associations
were most pronounced in the first trimester and among Hispanic women.

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    • "The distributions of the concentrations from the closest air monitoring station and weather variables during the entire pregnancy of the cohort of 95,911 pregnant women are shown in Table 1Based on our literature review, the pollution ranges were wider in this study than those in the majority of other published studies (Gehring et al., 2014;Pereira et al., 2014;Savitz et al., 2014;Ebisu and Bell, 2012;Brauer et al., 2008). Table 2shows Pearson correlation coefficients between pollutants . "
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    ABSTRACT: Importance: Although studies in western countries suggest that ambient air pollution is positively associated with adverse pregnancy outcomes, the upper levels of pollutant exposures have been relatively low, thus eroding confidence in the conclusions. Meanwhile, in Asia, where upper levels of exposure have been greater, there have been limited studies of the association between air pollution and adverse pregnancy outcomes. Objective: The primary objective was to evaluate whether high levels of pollution, including particulate matter pollution with a mass median aerodynamic diameter of less than 2.5μm (PM2.5) and 10μm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and carbon monoxide (CO) are related to increased occurrence of preterm birth (PTB). Methods: We conducted a population-based study in Wuhan, China in a cohort of 95,911 live births during a two-year period from 2011 to 2013. The exposure was estimated based on daily mean concentrations of pollutants estimated using the pollutants' measurements from the nine closest monitors. Logistic regressions were performed to determine the relationships between exposure to each of the pollutants during different pregnancy periods and PTB while controlling for key covariates. Results: We found 3% (OR=1.03; 95% CI: 1.02, 1.05), 2% (OR=1.02; 95% CI: 1.02, 1.03), 15% (OR=1.15; 95% CI: 1.11, 1.19), and 5% (OR=1.05; 95% CI: 1.02, 1.07) increases in risk of PTB with each 5-μg/m(3) increase in PM2.5 and PM10 concentrations, 100-μg/m(3) increase in CO concentrations, and 10-μg/m(3) increase in O3 concentrations, respectively. There was negligible evidence for associations for SO2 and NO2. The effects from two-pollutant models were similar to the estimated effects from single pollutant models. No critical exposure windows were identified consistently: the strongest effect for PTB was found in the second trimester for PM2.5, PM10, and CO, but for SO2 it was in the first trimester, second month, and third month. For NO2 it was in the first trimester and second month, and for O3, the third trimester. Conclusion: Findings reveal an association between air pollutants and PTB. However, more toxicological studies and prospective cohort studies with improved exposure assessments are needed to establish causality related to specific pollutants.
    Full-text · Article · Nov 2015 · International journal of hygiene and environmental health
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    • "e l s e v i e r . c o m / l o c a t e / t o x l e t and prematurity in humans (Bobak, 2000; Leem et al., 2006; Liu et al., 2003; Pereira et al., 2014; Ritz et al., 2007; Sagiv et al., 2005; Suh et al., 2009) and human and mice litters with a high proportion of females (Lichtenfels et al., 2007; Miraglia et al., 2013). A decrease in the number of viable fetuses and an increase in implantation failure were observed in female mice exposed to air pollution from the 10th day of life (Mohallem et al., 2005). "
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    ABSTRACT: This study aimed to verify the development of placental and systemic inflammation in rats exposed to fine particulate matter before or during pregnancy. Wistar rats were exposed to filtered air (control) or to a load of 600μg/m(3) of fine particles in the air. The gene expression of IL-1β, IL-4, IL-6, IL-10, INF-γ, TNF-α and Toll-like receptor 4 in the placenta was evaluated. The serum and placental concentrations of IL-1β, IL-4, IL-6, IL-10, INF-γ and TNF-α were measured. The total and differential blood leukocyte and blood platelet count was assessed. Compared to control animals, IL-4 content was elevated in the fetal portion of the placenta in rats exposed to air pollution before and during pregnancy. Increased IL-4 suggests that a placental inflammatory reaction may have occurred in response to exposure to fine particulate matter and that this cytokine was responsible, among possibly others factors, for resolution of the inflammatory reaction. Copyright © 2014. Published by Elsevier Ireland Ltd.
    Full-text · Article · Dec 2014 · Toxicology Letters
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    • "Future studies might benefit from exposure estimates less reliant on ground monitors, such as land-use or satellite-derived PM 2.5 . In this cohort , 41% of variation in gestational length was attributable to variation between pregnancies to the same woman, compared to 34% in the Connecticut study (Pereira et al., 2014), which might be explained by differences in health inequality. Studies with greater total variation in gestational length plus higher proportions of within-women variation in gestational length are better positioned for studies that adopt our longitudinal design. "
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    ABSTRACT: Objective A recent longitudinal study reported an association between fine particulate (PM2.5) exposure and preterm birth (PTB) in a US cohort. We applied the same design to an Australian cohort to investigate associations with PTB and pre-labor rupture of membranes (PROM). Methods From 287,680 births, we selected 39,189 women who had singleton births at least twice in Western Australia in 1997–2007 (n = 86,844 births). Analyses matched pregnancies to the same women with conditional logistic regression. Results For PROM adjusted odds ratios (ORs) for a 1 μg/m3 increase in PM2.5 in the first trimester, second trimester, third trimester, and whole pregnancy were 1.00 (95% confidence interval (CI): 0.97, 1.03), 1.03 (95% CI: 1.00, 1.06), 1.02 (95% CI: 1.00, 1.05), and 1.02 (95% CI: 0.99, 1.05) respectively. For PTB, corresponding ORs were 1.00 (95% CI: 0.96, 1.04), 1.00 (95% CI: 0.96, 1.04), 0.98 (95% CI: 0.94, 1.02), and 0.99 (95% CI: 0.95, 1.04) respectively. Conclusion Risk of PROM was greater for pregnancies with elevated PM2.5 exposure in the second trimester than were other pregnancies to the same Australian women at lower exposure. There was insufficient evidence for an association with PTB, indicating that a longer time period might be needed to observe an association if a causal effect exists.
    Full-text · Article · Dec 2014 · Environment International
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