Association between air pollution and preterm birth among neonates born in Isfahan, Iran.
BACKGROUND
Although several studies have investigated the association between maternal exposure to air pollution and preterm birth, the results are inconsistent. The aim of this study was to further investigate the relation between maternal exposure to ambient air pollution during pregnancy and the risk of preterm birth and low birth weight (LBW) in an Iranian pregnant population.


METHODS
In this study, we identified 4758 consecutive singleton birth records from one large referral hospital (2010-2012) in Isfahan, Iran. We identified cases of preterm birth and LBW, which were combined with meteorological and air pollution monitoring data. We estimated the effect of air pollution exposure during the entire pregnancy, each trimester, and last month, and preterm birth (gestational age <37 weeks) and LBW (<2500 g) by Pollutant Standard Index (PSI) using logistic regression adjusted for gestational age, neonate gender, birth order, and mother's age.


RESULTS
The PSI for entire pregnancy was significantly associated with preterm birth [Odds Ratio (95% CI) = 1.26 (1.20, 1.33)]. There was no association between maternal exposure to ambient air pollution and each trimester and the last month of pregnancy, and preterm birth or LBW.


CONCLUSIONS
Maternal exposure to ambient air pollution during the entire pregnancy was associated with preterm birth in Isfahani women.
Department of Epidemiology and Biostatistics, Isfahan University of Medical Sciences, Isfahan, Iran.
Mohsen
M
Janghorbani
Department of Epidemiology and Biostatistics, Isfahan University of Medical Sciences, Isfahan, Iran.
Elaheh
E
Piraei
Air pollution; Pollutant Standard Index; low birth weight; pregnancy outcome; premature birth; preterm delivery