Relationship between air pollution and pre-eclampsia in pregnant women: a case-control study.

Pre-eclampsia is the main cause of maternal and fetal death and disability worldwide. Its incidence in the Islamic Republic of Iran is 5%-12%. Air pollution has been reported to be one of the causative factors, and this case-control study determined its effect on pre-eclampsia in 195 pregnant women (65 with pre-eclampsia and 130 without) admitted to hospitals in Tehran. Women were divided into high and low exposure groups according to the mean density of exposure to pollutants during pregnancy. There was no statistically significant relationship between exposure to air pollutants including CO, particulate matter, SO2, NO2 and O3 and pre-eclampsia. The combined effect was also not significant. Air pollution is one of the problems of modern society and its avoidance is almost impossible for pregnant women. This study should reduce concern about pregnant women living in polluted cities.