Maternal smoking during pregnancy, polymorphic CYP1A1 and GSTM1, and lung-function measures in urban family children

► We examined prenatal tobacco exposure, xenometabolic genes, and child lung function in a low-income pediatric sample. ► Overall, maternal smoking during pregnancy was associated with significant reductions in key lung-function measures. ► Greater lung-function reductions were observed in children of smoking mothers who possessed the polymorphic CYP1A1*2A and GSTM1 deletion.