Mothers who are exposed to air pollution are at risk of giving birth to babies with a low birth weight, a study has shown.
Authors suggest that exposure to traffic pollution or living close to a major road during early and late pregnancy may restrict fetal growth.
The study, carried out at the University of Medicine and Dentistry of New Jersey, found that mothers who lived in areas with higher levels of nitrogen dioxide were more likely to give birth to babies with low birth weights.
The findings are based on 336,000 births between 1999 and 2003 in New Jersey, USA.
Researchers used air pollution readings from monitoring points within 6 miles of the mothers’ homes to calculate levels of exposure to average air pollution during the three trimesters of pregnancy.
The authors say: ‘Our findings suggest that ambient air pollution, perhaps specifically traffic emissions during early and late pregnancy and/or factors associated with residence near a roadway during pregnancy, may affect fetal growth.’
Authors point out that exactly how air pollution might restrict fetal growth is not clear, and its effects may differ between women with complicated and uncomplicated pregnancies.
Previous research suggests that air pollution might alter cell activity, or cut the amount of oxygen and nutrients a baby receives while in the womb.