Air pollution 'increases pregnancy hypertension risk'

The chances of pregnant women developing hypertension are increased if they are subjected to high levels of air pollution. Low air quality can lead to an increase in blood pressure within pregnant women, which can lead to complications that increase the risk for both mother and baby, such as preeclampsia, according to new research.

Researchers from the University of Florida, US, have found that women who are exposed to high levels of airborne pollutants during pregnancy are at a significantly increased risk for hypertension. The researchers compared air pollution level estimates from the Environmental Protection Agency with birth data. Pollutants that can affect pregnant women include sulphur dioxide, carbon monoxide and two forms of particulate matter, which include particles from metals, acids, dust and soil. 

Data from more than 22,000 women was included in the study, each of whom had given birth in Jacksonville between 2004 and 2005. Environmental data taken from each of the women's communities throughout the same period was also included in the research. The researchers did not include women who had previously had premature babies, suffered from chronic hypertension or had babies that were born with complications.

It was found that 4.7 per cent of the women included in the study developed a hypertensive disorder while pregnant. The chance of developing this complication increased when the women were exposed to high levels of air pollution during the first two trimesters of their pregnancy. 

This was determined once other factors that could lead to high blood pressure were identified, such as whether they smoked during pregnancy, their socioeconomic status and exposure to co-pollutants. However, the research could not prove conclusively whether air pollution exposure during the early or late stages of pregnancy was more likely to increase risk.  

The researchers suggested that these findings signal the need for stricter pollution controls in order to lessen overall health impacts, as well as the risks for expectant mothers. Implementing stricter regimes to cut down on air pollution could help reduce the number of complications that are experienced by both mothers and babies.