University of Florida ( UF ) researchers compared birth data with Environmental Protection Agency ( EPA ) estimates of air pollution, finding that heavy exposure to four air pollutants led to a significantly increased risk for developing a high blood pressure disorder during pregnancy.
The research was published in the Journal of Epidemiology & Community Health.
The pollutants include two specific types of fine and coarse particulate matter, carbon monoxide and sulfur dioxide. According to the EPA, particulate matter includes acids, dust, metals and soil particles. These inhalable particles are released from industries and forest fires and can form when gases react with each other in the air. Sulfur dioxide is emitted from power plants and industries. Most carbon monoxide is produced by car exhaust.
Fetal development is very sensitive to environmental factors. Hypertension, in particular, is associated with increased morbidity and mortality, causing a lot of problems for the mother and fetus, including preterm delivery.
Hypertensive disorders such as gestational hypertension, preeclampsia and the deadly condition it leads to, eclampsia, affect about 10 percent of pregnancies. Despite the serious risks to mother and baby, little is known about what specifically causes these conditions to develop in pregnant women.
To gain a better understanding of how environmental factors may play a role in increasing the risk of developing hypertension during pregnancy, the researchers examined data from women who gave birth in Jacksonville, Fla., between 2004 and 2005 and environmental data from their communities. The sample included more than 22,000 pregnant women.
The researchers did not include mothers with chronic hypertension, those who had previously given birth prematurely or those whose babies were born with other complications in the sample. They then gauged how much pollution the women were exposed to throughout their pregnancies using data the EPA gathered daily to measure the levels of several pollutants.
Among the sample of women, 4.7% developed a hypertensive disorder during pregnancy. Exposure to air pollutants throughout the first two trimesters of pregnancy increased women's risk of developing one of these conditions. They determined this after controlling for other factors that could affect a woman's risk for developing hypertension, such as socioeconomic status, exposure to co-pollutants and smoking during pregnancy. But they could not determine conclusively whether exposure early in the pregnancy or late in the pregnancy was more likely to increase a woman's risk for hypertension. ( Xagena )
Source: University of Florida, 2014