Air Pollution Exposure Before And During Pregnancy Increases Risk of Miscarriage, Heart Problems: Studies

The findings of two new studies suggest that the side effects of exposure to air pollution during pregnancy may be more far reaching than researchers previously believed.

In findings published last week in the Journal of the American Heart Association, researchers indicate that exposure to particulate matter even before a child is conceived was linked to an increased risk of heart dysfunction during the child’s adulthood.

The study involved a comparison of exposure to clean filtered air or particulate matter (PM) 2.5 among mice, who were exposed for 30 hours per week for three months. The levels of exposure were less than what the U.S. Environmental Protection Agency (EPA) sets for safe daily air quality standards.

The mice exposed to fresh air or air pollution were bred and offspring of the parents were analyzed at 3 months old using echocardiographs and other measures.

Researchers determined that infants born from parents exposed to air pollution before conception experienced heart problems as adults. The mice were young and otherwise healthy, but they experienced a variety of heart problems during the prime of their lives. This would have been the human equivalent age of 20 years old.

The heart function was impaired and mice exhibited inflammatory markers linked to increased heart disease. They also had markers of oxidative stress, where levels of beneficial antioxidants are low, and calcium regulatory proteins were altered, which are critical to the function of the beating heart.

This is the first study of its kind and shows effects of air pollution are not limited to pregnancy or postnatal times, but can be incurred before pregnancy.

In a second study published the same day in the medical journal Fertility and Sterility, researchers focused on the link between air pollution and miscarriage.

The crossover study included nearly 1,400 women who experienced spontaneous miscarriage and sought help at the University of Utah emergency room afterward from 2007 to 2015.

According to the findings, increases in miscarriage occurred after a spike in short-term exposure to air pollution.

Each 10 part per billion increase in 7-day average levels of nitrogen dioxide was associated with a 16% increased risk of spontaneous miscarriage.

Researchers measured levels of three common pollutants, fine particulate matter, nitrogen dioxide, and ozone. In the three to seven days after a spike in nitrogen dioxide, women experienced more miscarriages.

Both studies linked exposure to air pollution to increased risks to infants, including increased risk of miscarriage and increased risk of serious heart problems later in life. The studies highlight the risk air pollution poses to the health of unborn children.