Unhealthy Air Around Pregnant Mothers Tied to Child's Asthma

Air pollution exposure during the second trimester increased risk of baby having asthma as a child

/ Author:  / Reviewed by: Robert Carlson, M.D Beth Bolt, RPh

(RxWiki News) The foods that a woman eats during pregnancy can have a huge impact on her baby's development, both before and after birth. The quality of air that a pregnant woman breathes may be equally important to her baby's health.

A recent study found that the children whose mothers were exposed to high levels of air pollution during the second trimester of pregnancy had higher odds of developing asthma compared to children whose mothers were not exposed to high levels of air pollution during pregnancy.

The researchers discovered that the children affected by air pollution and asthma were those born to mothers who weren't obese.

"Discuss the risks of air pollution exposure during pregnancy with your OB/GYN."

The lead author of this study was Yueh-Hsiu Mathilda Chiu, ScD, from the Department of Pediatrics in the Icahn School of Medicine at Mount Sinai in New York, New York.

The study included 430 mothers who gave birth to a single child after 37 weeks of pregnancy. Of these mothers, 55 percent were Hispanic, 27 percent were black, and 66 percent had at most 12 years of education.

The mothers had been recruited for the study while they were pregnant.

The researchers used the mothers’ addresses to estimate their daily levels of exposure to air pollution sources, such as power plants, traffic and other industrial sources, made up of fine particles (less than 2.5 micrometers across).

Previous studies have shown that fine particles in air pollution are more likely to be inhaled than larger pollution particles; therefore, exposure to fine particles has been linked to an increased health risk.

The mothers and children were followed through reports submitted by the mothers until the children were 7 years old.

The findings showed that 18 percent of the children had asthma.

Dr. Chiu and team determined that the children born to non-obese mothers were most affected by air pollution during their mother's second trimester (13 to 27 weeks or pregnancy). 

For every increase of 10 micrograms per cubic meter in daily exposure to fine particles, the babies born to non-obese mothers had 35 percent increased odds of developing asthma.

The researchers found that the association was not significant for the children who were born to obese mothers.

Lastly, the findings revealed that there was a three-way association between average levels of exposure to fine particles at 13 to 27 weeks, the babies’ gender and the mothers’ weight. In other words, exposure, gender and mother's weight all affected each other.

"While we should continue to improve air quality and minimize exposure to pregnant women throughout the entire pregnancy for a host of health reasons, pinpointing the gestational period during which air pollution has the greatest effects on the developing lung may add to our understanding of the mechanisms underlying this relationship," said co-author Rosalind Wright, MD MPH, from the Department of Pediatrics at Icahn School of Medicine at Mount Sinai, in a press statement.

This study was presented on May 19 at the 2014 American Thoracic Society International Conference.

Review Date: 
May 19, 2014
Last Updated:
May 20, 2014