High peak PM2.5 exposure during pregnancy and preterm birth risk in Utah, USA
Year: 2019
Type: conference-abstract
Abstract: OPS 54: Air pollution and pregnancy outcomes, Room 117, Floor 1, August 28, 2019, 1:30 PM - 3:00 PM Background/Aim: Studies of preterm birth (≤37 weeks) in association with air pollution have primarily examined chronic average exposures for whole pregnancies/trimesters. Utah is known for valley air inversions which cause relatively short intervals of high exposure to particulate matter <2.5 microns (PM2.5). We examined peak exposures to evaluate whether experiencing particularly high levels during any week of gestation was associated with preterm risk. Methods: PM2.5 was estimated by modified CMAQ models. We classified peaks as a weekly average of >35 ug/m3, which is the US 24-hour regulatory standard, or >18.23 ug/m3, the 95th percentile in our data. Clinical information, including gestational age, was derived from electronic hospital records for 112,203 pregnancies among 50,005 women delivering at 20 Utah hospitals. Results: The preterm birth rate was 7.7%. During each week of gestation, 9.5-13.0/1,000 pregnancies were exposed to an average PM2.5 >35 ug/m3 and 50.6-67.0/1,000 exposed to >18.23 ug/m3. At least one peak exposure week was experienced in 33.5% of pregnancies. Modified Poisson regression models with generalized estimating equations to control for multiple pregnancies to the same woman were adjusted for maternal age, race/ethnicity, BMI, smoking, alcohol use, parity, insurance status, marital status, asthma and ambient temperature. For each first trimester peak exposure week, the relative risk (RR) of preterm birth increased 5-6% (>35 ug/m3 RR=1.06; 95% CI=1.01-1.11; >18.23 ug/m3 RR=1.05; 95% CI=1.02-1.07). Similar results were seen considering the proportion of peak weeks over the whole pregnancy with 3-4% increases (>35 ug/m3 RR=1.04; 95% CI=1.00-1.08; >18.23 ug/m3 RR=1.03; 95% CI=1.01-1.05) and during the first 28 weeks with 2-3% increases (>35 ug/m3 RR=1.03; 95% CI=0.99-1.06; >18.23 ug/m3 RR=1.02; 95% CI=1.01-1.04). Second trimester results were null. Conclusions: We found that even one high week of exposure, particularly in the first trimester, was associated with increased preterm birth in a population of low-risk women.
Source: Environmental Epidemiology
Language: English
Subfield: Health, Toxicology and Mutagenesis
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,200
OpenAlex ID: W2981587131