In-womb air pollution associated with higher blood pressure in childhood
Children who were exposed to higher levels of air pollution during the third trimester of their mother’s pregnancy had a higher risk of elevated blood pressure in childhood, according to new research in the American Heart Association’s journal Hypertension.
Fine particulate matter of 2.5 microns or less (PM2.5) is a form of air pollution produced by motor vehicles and the burning of oil, coal and biomass, and has been shown to enter the circulatory system and negatively affect human health.
Previous studies found, direct exposure to fine air pollution was associated with high blood pressure in both children and adults and is a major contributor to illness and premature death worldwide.
“Ours is one of the first studies to show breathing polluted air during pregnancy may have a direct negative influence on the cardiovascular health of the offspring during childhood,” said Noel T. Mueller, Ph.D., M.P.H., senior author of the study and an assistant professor of epidemiology at the Johns Hopkins University Bloomberg School of Public Health in Baltimore, Maryland.
“High blood pressure during childhood often leads to high blood pressure in adulthood and hypertension is the leading cause of cardiovascular disease.”
Researchers examined 1,293 mothers and their children who were part of the large, ongoing Boston Birth Cohort study. Blood pressure was measured at each childhood physical examination at 3- to 9- years old.
A systolic (top number) blood pressure was considered elevated if it was in the highest 10 percent for children the same age on national data. Researchers also adjusted for other factors known to influence childhood blood pressure, such as birth weight and maternal smoking.