A large international study confirms that children exposed to cigarette smoke in utero and after birth have an increased risk of impaired lung function (Moshammer H et al. Am J Respir Crit Care Med. 2006;173:1255-1263).
The researchers analyzed respiratory flow and volume data of 22 712 children from 9 countries in Europe and North America, about 60% of whom had been exposed to cigarette smoke prenatally or in early life. Children whose mothers smoked during pregnancy were up to 40% more likely to have poor lung function (defined as the lowest 5% lung function based on defined cutoff points for the parameters measured) than children born to nonsmokers. Exposure in the first 2 years of life was associated with reduced lung function, independent of parental smoking status during pregnancy.
Stephenson J. Parental Smoking. JAMA. 2006;296(3):272. doi:10.1001/jama.296.3.272-b