The association between prenatal exposure to cigarette smoke, alcohol, and coffee and the risk of febrile seizures was evaluated by extracting information from records of 2 cohorts of children linked with the Danish National Hospital Register and a follow-up of patients until Dec 1998. A slightly increased risk for febrile seizures was found in children exposed to 10 or more cigarettes daily in one cohort (p=0.04), but in the other cohort, this association was weak (p=0.54). The cumulative incidence of febrile seizures was 4.4% and 4.0%, respectively, in children exposed in the 2 cohorts, compared to 3.5% and 3.4% in those not exposed. Hazard ratios were 1.25 and 1.09, respectively. No association was found between low to moderate levels of maternal alcohol and coffee consumption and the risk for febrile seizures, either simple or complex in type. 
COMMENT. The risk of febrile seizures may be increased in children exposed to moderate nicotine levels in utero. In some previous studies, prenatal smoking was associated with a 2-fold increased risk of febrile seizures, and the risk was increased with the number of cigarettes smoked daily.