Acute and recent air pollution exposure and cardiovascular events at labour and delivery

Abstract

Objective To study the relationship between acute air pollution exposure and cardiovascular events during labour/delivery. Methods The Consortium on Safe Labor (2002–2008), an observational US cohort with 223 502 singleton deliveries provided electronic medical records. Air pollution exposure was estimated by modified Community Multiscale Air Quality models. Cardiovascular events (cardiac failure/arrest, stroke, myocardial infarcts and other events) were recorded in the hospital discharge records for 687 pregnancies (0.3%). Logistic regression with generalised estimating equations estimated the relationship between cardiovascular events and daily air pollutant levels for delivery day and the 7 days preceding delivery. Results Increased odds of cardiovascular events were observed for each IQR increase in exposure to nitric oxides at 5 and 6 days prior to delivery (OR=1.17, 99% CI 1.04 to 1.30 and OR=1.15, 1.03 to 1.28, respectively). High exposure to toxic air pollution species such as ethylbenzene (OR=1.50, 1.08 to 2.09), m-xylene (OR=1.54, 1.11 to 2.13), o-xylene (OR=1.51, 1.09 to 2.09), p-xylene (OR=1.43, 1.03 to 1.99) and toluene (OR=1.42, 1.02 to 1.97) at 5 days prior to delivery were also associated with cardiovascular events. Decreased odds of events were observed with exposure to ozone. Conclusions Air pollution in the days prior to delivery, especially nitrogen oxides and some toxic air pollution species, was associated with increased risk of cardiovascular events during the labour/delivery admission.

Ambient temperature and risk of cardiovascular events at labor and delivery: A case-crossover study

“…One factor potentially contributing to this upward trend is the shift in population-level cardiovascular risk factors including maternal age, obesity, and gestational complications (Ferrara, 2007; Lu et al, 2001). Although the incidence of cardiovascular events during labor and delivery is relatively low at 0.3% (Männistö et al, 2015), in addition to being potentially life-threatening, these events have long-term implications for affected women and their families (Sliwa and Bohm, 2014). Consequently, it is critical to identify and understand potentially modifiable risk factors.…”

“…Consequently, it is critical to identify and understand potentially modifiable risk factors. Our group has published some early evidence on the potential acute association between ambient air pollution and the risk of cardiovascular events at labor and delivery (Männistö et al, 2015), but other environment risk factors are largely unknown.…”

Air pollution and cardiovascular events at labor and delivery: a case-crossover analysis

“…We recently published the first study estimating the odds of cardiovascular events at labor/delivery associated with air pollution exposure during the week preceding delivery in a multi-site U.S. obstetric cohort. 8 Although our study population consisted of mainly young and healthy pregnant women, we were concerned about residual chronic confounding, particularly due to genetic susceptibility, underlying health status (especially concerning the cardiovascular system), and other pregnancy-related conditions with potential acute-on-chronic exacerbations, which may have potentially affected our results. 9 To account for these non-time varying confounding factors, in the present study we examined the associations between acute and recent exposures to air pollutant exposures and odds of having a labor/delivery with cardiovascular events including ischemic heart disease, stroke, heart failure, cardiac arrest/failure, and other or unspecified cardiovascular events, using a case-crossover study design.…”

Air pollution and cardiovascular hospital admissions in Kerman, Iran

“…Uncontrolled urban expansion along with rapid economic development and increased energy consumption has caused numerous environmental problems for humans [1,2] . In the recent years, human's activities have made alarming changes in ambient air pollutants that lead to climate change and serious health consequences [3] .…”