Recent reports have shown that air pollution may increase the risk of adverse birth outcomes. We have evaluated the relationship between ambient air pollution and the occurrence of preterm delivery using routinely collected data in Lithuania.
his epidemiological study comprised all singleton newborns (N = 3,988), born to women in 1998, who resided in the City of Kaunas. Birth data and information on maternal characteristics were obtained from the Lithuanian National Birth Register. To estimate residential exposure levels, we used measurements of ambient nitrogen dioxide (NO2) and formaldehyde, which were collected at 12 monitoring posts. Multivariate logistic regression was used to estimate the effect that each pollutant would have on premature birth while controlling for potential confounders.
Adjusted ORs of preterm birth for the medium and high NO2 tertile exposures were OR = 1.14 (95% CI 0.77–1.68) and OR = 1.68 (95% CI 1.15–2.46), respectively. The risk of preterm birth increased by 25% (adjusted OR = 1.25, 95% CI 1.07–1.46) per 10#61549;g/m3 increase in NO2 concentrations. An analysis of specific exposures by trimester revealed an increased risk of pre-maturity associated with first-trimester exposure to NO2 (adjusted OR = 1.67; 95% CI 1.28–2.18). There were no significant relationships in either pregnancy period between preterm birth and exposure to formaldehyde.
Our findings suggest that in the City of Kaunas there might be a relationship between maternal exposure to NO2 and the risk of preterm birth.