Geospatial analyses of adverse birth outcomes in Southwestern Ontario: Examining the impact of environmental factors

Jamie A Seabrook; Alexandra Smith; Andrew F Clark; Jason A Gilliland

doi:10.1016/j.envres.2018.12.068

Geospatial analyses of adverse birth outcomes in Southwestern Ontario: Examining the impact of environmental factors

Environ Res. 2019 May:172:18-26. doi: 10.1016/j.envres.2018.12.068. Epub 2018 Dec 31.

Authors

Jamie A Seabrook¹, Alexandra Smith², Andrew F Clark³, Jason A Gilliland⁴

Affiliations

¹ School of Food and Nutritional Sciences, Brescia University College, 1285 Western Road, London, Ontario, Canada, N6G 1H2; Department of Paediatrics, Western University, 800 Commissioners Road East, London, Ontario, Canada, N6A 5W9; Department of Epidemiology and Biostatistics, Western University, 1151 Richmond Street, London, Ontario, Canada, N6A 5C1; Children's Health Research Institute, 800 Commissioners Road East, London, Ontario, Canada, N6C 2V5; Lawson Health Research Institute, 750 Base Line Road East, London, Ontario, Canada, N6C 2R5; Human Environments Analysis Laboratory, Western University, 1151 Richmond Street, London, Ontario, Canada, N6A 3K7.
² School of Food and Nutritional Sciences, Brescia University College, 1285 Western Road, London, Ontario, Canada, N6G 1H2.
³ Children's Health Research Institute, 800 Commissioners Road East, London, Ontario, Canada, N6C 2V5; Human Environments Analysis Laboratory, Western University, 1151 Richmond Street, London, Ontario, Canada, N6A 3K7; Department of Geography, Western University, 1151 Richmond Street, London, Ontario, Canada, N6A 5C2.
⁴ Department of Paediatrics, Western University, 800 Commissioners Road East, London, Ontario, Canada, N6A 5W9; Department of Epidemiology and Biostatistics, Western University, 1151 Richmond Street, London, Ontario, Canada, N6A 5C1; Children's Health Research Institute, 800 Commissioners Road East, London, Ontario, Canada, N6C 2V5; Lawson Health Research Institute, 750 Base Line Road East, London, Ontario, Canada, N6C 2R5; Human Environments Analysis Laboratory, Western University, 1151 Richmond Street, London, Ontario, Canada, N6A 3K7; Department of Geography, Western University, 1151 Richmond Street, London, Ontario, Canada, N6A 5C2; School of Health Studies, Western University, 1151 Richmond Street, London, Ontario, Canada, N6A 3K7. Electronic address: jgillila@uwo.ca.

PMID: 30769185
DOI: 10.1016/j.envres.2018.12.068

Abstract

Background: A growing body of research has examined the association between exposure to environmental factors during pregnancy and adverse birth outcomes; however, many studies do not control for potential covariates and findings vary considerably.

Objective: To test the relative influence of environmental factors including exposure to air pollution, major roads, highways, industry, parks, greenspaces, and food retailers on low birth weight (LBW) and preterm birth (PTB) in Southwestern Ontario (SWO), Canada, while accounting for medical (e.g., previous preterm birth, gestational diabetes), behavioral (e.g., alcohol, smoking), demographic (e.g., maternal age, body mass index), and neighborhood-level socioeconomic (e.g., household income, education) factors.

Methods: This retrospective cohort study consisted of a large sample of pregnant women from SWO who gave birth to singleton newborns between February 2009 and February 2014 at London Health Sciences Centre. Data on maternal postal codes were entered into a Geographic Information System to map the distribution of maternal residences and determine selected characteristics of their neighborhood environments (i.e., socioeconomic, built, natural). These variables were developed based on postal codes where the mothers lived prior to giving birth. Logistic regression was used to assess the relative effects of the physical environment, socioeconomic status, clinical history, and behavioral risk factors on mothers having a LBW or PTB infant.

Results: Out of 25,263 live births, 5.7% were LBW and 7.5% were PTB. Exposure to sulfur dioxide was a top predictor of both LBW and PTB. For every one-unit increase in sulfur dioxide, the odds of a LBW and PTB were 3.4 (95% CI: 2.2, 5.2) and 2.0 (95% CI: 1.4, 3.0) times higher, after controlling for other variables in the model, respectively (p < 0.001). Previous PTB was also highly associated with both birth outcomes.

Conclusions: Health care providers should be informed about the hazards of air pollution to developing fetuses so that recommendations can be made to their pregnant patients about limiting exposure when air quality is poor.

Keywords: Air pollution; Infant; Low birth weight; Premature birth; Sulfur dioxide.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cohort Studies
Environmental Exposure
Female
Geographic Information Systems
Humans
Infant, Low Birth Weight*
Infant, Newborn
Ontario / epidemiology
Pregnancy
Pregnancy Outcome* / epidemiology
Premature Birth* / epidemiology
Retrospective Studies
Risk Factors