Cigarette smoke and unborn babies don’t mix. Pregnant moms may be able to control secondhand smoke exposure at home. But in public places, smoking bans are the only protection.
A recent study looked at rates of premature births in Belgium in relation to the passing of smoking bans in public places.
Researchers found a 3 percent reduction in premature births for every year smoke-free policies were in place between 2007 and 2011.
The authors concluded that exposure to secondhand smoke could increase the risk of having a preterm delivery.
Bianca Cox, PhD student at the Centre for Environmental Sciences at Hasselt University in Belgium, and Tim Nawrot, PhD, associate professor of environmental epidemiology at the Department of Public Health at the University of Leuven in Belgium, worked with a team of fellow scientists to investigate the impact of smoking bans on premature births.
While this study was based on smoking bans and premature births in Belgium, cities across the United States have enacted similar bans.
In Belgium, smoke-free laws were passed in three phases: no smoking in workplaces in 2006, no smoking in restaurants in 2007 and no smoking in bars serving food in 2010.
For this study, researchers collected data from 2002 through 2011 on 448,520 single (not twin or multiple), non-induced births between 24 to 44 weeks of pregnancy. Babies born before 37 weeks of pregnancy were considered premature or preterm.
From 2002 to 2006, prior to the no-smoking laws, researchers found no changes in rates of premature births. By 2007, when the ban on smoking in restaurants had been in place for one year, premature births decreased by 3 percent.
Researchers found premature births continued to decrease by 3 percent every year between 2007 and 2011.
The following variables were all taken into account: infant gender, maternal age, socioeconomic status, urban or rural setting, the mother’s nation of origin, time of the year, influenza epidemics, air pollution and temperature changes.
None of the variables mentioned above could explain the drop in premature births aside from the no-smoking laws.
The authors concluded that smoking bans in public places lowered the risk of premature births, and that expectant mothers should avoid secondhand smoke exposure.
This study was published in February in the BMJ.
The Study Centre for Perinatal Epidemiology, the Flemish Centre for Care and Health, the Flemish Scientific Fund and the Hasselt University Fund provided financial support for this project. No conflicts of interest were declared.