MONDAY, Dec. 11, 2017 (HealthDay News) -- Women who are exposed to air pollution right before or after they become pregnant may be more likely to have a baby with birth defects, new research suggests.
The increased risk is modest, but scientists say their findings warrant more investigation since all pregnant women are exposed to some level of pollution.
"The most susceptible time of exposure appears to be the one month before and after conception," said study senior author Dr. Emily DeFranco, a physician at Cincinnati Children's Hospital Medical Center.
"Public health efforts should continue to highlight the importance of minimizing population-level exposure to harmful particulate matter in the air," she added in a hospital news release.
For the study, the researchers investigated the effects of fine particulate matter -- tiny particles and droplets of liquid that get into the air. Once inhaled, they can become trapped deep in the lungs and enter the bloodstream.
The scientists examined data on particulate matter collected by the U.S. Environmental Protection Agency at 57 different monitoring stations in Ohio.
The investigators also compiled birth certificate data from the Ohio Department of Health, which included the mothers' addresses. The researchers then analyzed the link between the women's exposure to air pollution and birth defects among their babies.
Although the study found an association between exposure to air pollution and birth defects, DeFranco noted that because it was an observational study, it cannot prove a cause-and-effect link.
Birth defects -- including abnormal hearts and cleft lip or palate -- affect 3 percent of all births in the United States, the study authors noted.
The report was published online Dec. 11 in The Journal of Pediatrics.
The U.S. National Institute of Environmental Health Sciences has more about air pollution.