Objectives-Outdoor air pollution has consistently been shown to predict mortality.

The finding that this association is stronger in infants than in children or adults raises the question whether air pollution could also be related to pregnancy outcomes-such as birthweight and still-birth.

The association between outdoor air pollution and stillbirths and low birthweight in the Czech Republic, where air pollution was high, was examined.

Methods-An ecological study was conducted, with routinely collected data on stillbirths and low birthweight (<2500 g), air pollution (total suspended particulates, sulphur dioxide (SO2), and nitrogen oxides (NOx)), and socioeconomic factors (mean income, car ownership, divorce rate, etc).

The analyses were restricted to 45 districts on which data on air pollution were available for the period 1986-8.

The effects of exposure variables on frequency of pregnancy outcomes were estimated by logistic regression with district-years as the units of analysis.

Results

Stillbirth rate (4.211000 births in monitored districts) was not significantly associated with any indicator of air pollution, and was weakly related to mean income and proportion of births outside marriage.

Crude prevalence of low birthweight (prevalence 5.5%) showed highly significant associations with several socioeconomic factors ; after controlling for these, odds ratios (ORs)/50 mug/m3 increase in pollutant were : 1.04 (95% confidence interval (95% CI) 0.96 to 1. (...)