Cigarette Smoking and Birth Weight

"Consistent with previous studies, we found that maternal cigarette smoking was associated with reduced birth weight and an increased risk of LBW,^3-8 shortened gestation and an increased risk of preterm birth,^8,27-29 and intrauterine growth restriction.^3,9,10 Our data indicate that maternal cigarette smoking likely affects infant birth weight via both reduced fetal growth and shortened gestation. More importantly, our study shows consistent evidence that the adverse effects of maternal cigarette smoking on infant birth weight and gestational age were modified by maternal CYP1A1 and GSTT1 genotypes. Our data demonstrate that a subgroup of pregnant women with certain genotypes appeared to be particularly susceptible to the adverse effect of cigarette smoke, suggesting an interaction between metabolic genes and cigarette smoking."