Preliminary Study to Determine the Association between Maternal Exposure to Fine Particulate Matter (PM2.5) and Adverse Pregnancy Outcomes in Lima, Peru

Abstract

Environmental exposure to fine particulate matter (PM) is associated with increased risks for respiratory and cardiovascular diseases as well as some kinds of cancer and pregnancy adverse outcomes. Among others, Lima, a mega city located in Peru, has been considered one of the most contaminated cities in Latin America with mean annual concentrations of PM2.5 ranging from 35 to 16 μg/m3 (mean value: 26 μg/m3). Besides that, there are no studies related to the effect of outdoor PM air pollution on pregnancy outcomes in Lima, Peru. The aim of this preliminary study is to determine the association between maternal exposure to PM2.5 on pregnancy outcomes in a hospital-based linkage study in the metropolitan area of Lima. This study analyzes the data corresponding to the period between January 2007 and December 2009. Newborn data were obtained through the Perinatal Information System (SIP 2000 in Spanish) from two public hospitals in Lima, Peru. Preterm birth (PTB), small for gestational age (SGA) and birth weight (BW) were considered as pregnancy outcomes. Also, records of PM2.5 during this same period were recorded. Linear and logistic regression analyses were used to predict adverse pregnancy outcomes associated with PM2.5 exposure. Data included 4,173 births. Of the three pregnancy outcomes, the exposure to higher concentrations of PM2.5 (3rd quartile) were associated with an elevated risk of preterm birth in the 1st trimester (OR 1.62, CI95% 1.06 – 2.49), 2nd trimester (OR 1.71, CI95% 1.13 - 2.58), and 3rd trimester (OR=1.87, CI95|% 1.27 – 2.76). To sum up, maternal exposure to PM2.5 during pregnancy increase risks for preterm births. Future studies are being carried out to expand the years of exposure according to the use of time-series analysis and the collection of current newborn data.