Maternal Exposure to Particulate Air Pollution and Term Birth Weight: A Multi-Country Evaluation of Effect and Heterogeneity

• Authors: Payam Dadvand, Centre for Research in Environmental Epidemiology (CREAL); Jennifer Parker, Centers for Disease Control and Prevention; Michelle L. Bell, Yale University; Matteo Bonzini, University of Insubria; Michael Brauer, University of British Columbia; Lyndsey Darrow, Emory University; Ulrike Gehring, University of Utrecht; Svetlana V. Glinianaia, Newcastle University; Nelson Gouveia, University of São Paulo; Eun-hee Ha Ha, Ewha Womans University; Jong Han Leem, Inha University; Edith H. van den Hooven, Erasmus Medical Center; Bin Jalaludin, Evidence Management and Surveillance; Bill M. Jesdale, University of California Berkeley; Johanna Lepeule, Harvard University; Rachel Morello-Frosch, University of California Berkeley; Geoffrey G. Morgan, North Coast Area Health Service; Angela Cecilia Pesatori, University of Milan; Frank H. Pierik, Urban Environment and Safety, TNO; Tanja Pless-Mulloli, Newcastle University; David Q. Rich, University of Rochester; Sheela Sathyanarayana, University of Washington; Juhee Seo, Ewha Womans University; Rémy Slama, INSERM; Matthew Strickland, Emory University; Lillian Tamburic, University of British Columbia; Daniel Wartenberg, University of Medicine & Dentistry New Jersey; Mark J. Nieuwenhuijsen, Centre for Research in Environmental Epidemiology (CREAL); Tracey J. Woodruff, University of California San Francisco
• Journal Title: Environmental Health Perspectives
• Volume: Volume 121, Number 3
• Publisher: National Institute of Environmental Health Sciences (NIEHS) | 2013-03-01, Pages 367-373
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1289/ehp.1205575
• Subjects: Health Sciences, Public Health; Health Sciences, Epidemiology
• Keywords: Science & Technology; Life Sciences & Biomedicine; Environmental Sciences; Public, Environmental & Occupational Health; Toxicology; Environmental Sciences & Ecology; ENVIRONMENTAL SCIENCES; PUBLIC, ENVIRONMENTAL & OCCUPATIONAL HEALTH, SCI; air pollution; fetal growth; heterogeneity; ICAPPO; low birth weight; meta-analysis; meta-regression; multi-center study; particulate matter; pregnancy; PREGNANCY OUTCOMES; METAANALYSIS; RISK; INFANTS; HEALTH

Abstract

Background: A growing body of evidence has associated maternal exposure to air pollution with adverse effects on fetal growth; however, the existing literature is inconsistent. Objectives: We aimed to quantify the association between maternal exposure to particulate air pollution and term birth weight and low birth weight (LBW) across 14 centers from 9 countries, and to explore the influence of site characteristics and exposure assessment methods on between-center heterogeneity in this association. Methods: Using a common analytical protocol, International Collaboration on Air Pollution and Pregnancy Outcomes (ICAPPO) centers generated effect estimates for term LBW and continuous birth weight associated with PM10 and PM2.5 (particulate matter ≤ 10 and 2.5 μm). We used meta-analysis to combine the estimates of effect across centers (~ 3 million births) and used meta-regression to evaluate the influence of center characteristics and exposure assessment methods on between-center heterogeneity in reported effect estimates. Results: In random-effects meta-analyses, term LBW was positively associated with a 10-μg/m3 increase in PM10 [odds ratio (OR) = 1.03; 95% CI: 1.01, 1.05] and PM2.5 (OR = 1.10; 95% CI: 1.03, 1.18) exposure during the entire pregnancy, adjusted for maternal socioeconomic status. A 10-μg/m3 increase in PM10 exposure was also negatively associated with term birth weight as a continuous outcome in the fully adjusted random-effects meta-analyses (-8.9 g; 95% CI: -13.2, -4.6 g). Meta-regressions revealed that centers with higher median PM2.5 levels and PM2.5:PM10 ratios, and centers that used a temporal exposure assessment (compared with spatiotemporal), tended to report stronger associations. Conclusion: Maternal exposure to particulate pollution was associated with LBW at term across study populations. We detected three site characteristics and aspects of exposure assessment methodology that appeared to contribute to the variation in associations reported by centers.