Air pollution exposure and adverse pregnancy outcomes in a large UK birth cohort: use of a novel spatio-temporal modelling technique

Abstract

This paper uses a novel air pollution modelling technique to capture strong spatial and temporal resolution in order to assign exposure estimates to a large cohort, reducing the risk of exposure misclassification. The association between air pollution and adverse pregnancy outcomes is quantified in North West England -an area where this has not been investigated before. Affiliation 518Scand J Work Environ Health 2014, vol 40, no 5 Original article Scand J Work Environ Health. 2014;40(5):518-530. doi:10.5271/sjweh.3423 Air pollution exposure and adverse pregnancy outcomes in a large UK birth cohort: use of a novel spatio-temporal modelling technique By Kimberly Hannam, PhD,1,2, 3 Roseanne McNamee, PhD, 3 Philip Baker, MD, 4 Colin Sibley, PhD,1, 2 Raymond Agius, MD 5 Hannam K, McNamee R, Baker P, Sibley C, Agius R. Air pollution exposure and adverse pregnancy outcomes in a large UK birth cohort: use of a novel spatio-temporal modelling technique. Scand J Work Environ Health. 2014;40(5):518-530 doi:10.5271/sjweh.3423Objectives Previous work suggests an association between air pollution exposure and adverse pregnancy outcomes, even at relatively low concentrations. Our aim was to quantify the effect of air pollution having an adverse effect on preterm birth (PTB) and fetal growth in a large UK cohort using a novel exposure estimation technique [spatio-temporal (S-T) model] alongside a traditional nearest stationary monitor technique (NSTAT).Methods All available postcodes from a Northwest England birth outcome dataset during 2004-2008 were geocoded (N=203 562 deliveries). Pollution estimates were linked to corresponding pregnancy periods using temporally adjusted background modelled concentrations as well as NSTAT. Associations with PTB, small for gestational age (SGA), and birth weight were investigated using regression models adjusting for maternal age, ethnicity, parity, birth season, socioeconomic status (SES), body mass index (BMI), and smoking.Results Based on the novel S-T model, a small statistically significant association was observed for particulate matter (PM 10 ) and SGA, particularly with exposure in the first and third trimesters. Similar effects on SGA were also found for nitrogen dioxide (NO 2 ), particulate matter (PM 2,5 ), and carbon monoxide (CO) in later pregnancy, but no overall increased risk was observed. No associations were found with NO x or the outcomes PTB and reduction in birth weight. ConclusionOur findings suggest an association between air pollution exposure and birth of a SGA infant, particularly in the later stages of pregnancy but not with PTB or mean birth weight change.Key terms England; exposure estimation; preterm birth; SGA; small-for-gestational age; spatio-temporal model. Pregnancy outcome is determined by the ability of the fetus to thrive, which depends on a complex combination of genetic, social, and environmental factors (1). If, during pregnancy, a mother is exposed to increased environmental or social stressors, this could result in an increased risk of re...

Sex-specific differences in fetal growth in newborns exposed prenatally to traffic-related air pollution in the PELAGIE mother–child cohort (Brittany, France)

“…Although some of these significant associations might be pure chance findings, this is not likely to explain the consistent and significant associations observed across the four different metrics used to assess fetal growth. Our results are in line with some recent studies also reporting a decreased risk of low birth weight at term or higher birth weights associated with prenatal exposure to NO 2 (Laurent et al, 2013;Kashima et al, 2011;Hannam et al, 2014) or other air pollutants (Vinikoor-Imler et al, 2014;Laurent et al, 2013;Sellier et al, 2014;Madsen et al, 2010). In a recent meta-analysis on this topic, Stieb et al observed a high degree of heterogeneity among studies as measured by the I² value (Stieb et al, 2012).…”

Fetal growth and maternal exposure to particulate air pollution -- More marked effects at lower exposure and modification by gestational duration

“…Another study showed an association between SGA and exposure to PM 10 in the second trimester, with an OR of 1.01 (95% CI: 1.00, 1.04) for a 1 mg/m 3 increase (Mannes et al, 2005). Hannam et al (2014) found a significant association between SGA and entire pregnancy PM 10 exposure (OR for an increase from the 1st to the 4th quartile: 1.14, 95% CI: 1.01, 1.29).…”

Ambient air pollutant PM10 and risk of preterm birth in Lanzhou, China

“…While environmental chemical exposures have been suggested as potential risk factors for PB, such as phthalate diesters (Ferguson et al,2014), organochlorine pesticides, (Kadhel et al,2014; Longnecker et al,2001), and polychlorinated biphenyls (PCBs) (Helmfrid et al,2012; Taylor et al,1984), recent evidence suggests that ambient air pollution may play a role in PB (Brauer et al,2008; Dadvand et al,2013; Darrow et al,2009; Hannam et al,2014; Hansen et al,2006; Hyder et al,2014; Jiang et al,2007; Kim et al,2007; Lee et al,2013; Pereira et al,2014; Ritz et al,2000; Rojas-Rueda et al,2013; Rudra et al,2011; Sagiv et al,2005; Schifano et al,2013; Suh et al,2009; van den Hooven et al,2012; Wilhelm and Ritz,2005; Wilhelm et al,2011; Yorifuji et al,2011; Zhao et al,2011). Further, air pollution has been associated with other adverse birth outcomes such as low birth weight, small for gestational age, and birth defects (Ha et al,2014; Harris et al,2014; Hwang et al,2011; Vinikoor-Imler et al,2014).…”

“…While a majority of the preterm birth studies suggested that maternal exposure to high levels of PM with aerodynamic diameter no larger than 2.5µm (PM 2.5 ) or 10µm (PM 10 ) during pregnancy was a risk factor for PB (Brauer et al,2008; Dadvand et al,2013; Hansen et al,2006; Hyder et al,2014; Jiang et al,2007; Kim et al,2007; Lee et al,2013; Pereira et al,2014; Ritz et al,2000; Rojas-Rueda et al,2013; Sagiv et al,2005; Schifano et al,2013; Suh et al,2009; van den Hooven et al,2012; Wilhelm and Ritz,2005; Wilhelm et al,2011; Zhao et al,2011), others found no association (Darrow et al,2009; Hannam et al,2014; Rudra et al,2011). Most of these studies were conducted in Europe and United States where the air pollution levels are generally low.…”

“…Most of these studies were conducted in Europe and United States where the air pollution levels are generally low. In addition, the majority of early studies were based on registry or administrative databases (Brauer et al,2008; Darrow et al,2009; Hannam et al,2014; Hansen et al,2006; Hyder et al,2014; Jiang et al,2007; Pereira et al,2014; Ritz et al,2000; Rojas-Rueda et al,2013; Sagiv et al,2005; Suh et al,2009; Wilhelm and Ritz,2005; Wilhelm et al,2011; Zhao et al,2011). These databases, while useful, have limitations including lack of detailed information on confounding factors.…”