Risk of febrile seizures in childhood in relation to prenatal maternal cigarette smoking and alcohol intake.

The case-control study of febrile seizures in childhood described here, comprising 472 case-control pairs in western Washington, was designed to investigate the importance of prenatal exposures as risk factors for febrile seizures and to determine the degree to which two clinical subtypes of febrile seizures (simple and complex) have different risk factors. Maternal cigarette smoking and alcohol intake during pregnancy were associated with the risk of a febrile seizure in the child. Prenatal maternal cigarette smoking was associated with a twofold increase in the risk of a simple febrile seizure (95% confidence interval 1.2-3.4), and a strong dose-response relation was found. This association could not be explained by maternal demographic variables, maternal alcohol intake, child's birth weight, or childhood medical history variables. Prenatal maternal alcohol intake was associated with a twofold increase in the risk of a complex febrile seizure (95% confidence interval 1.3-3.8), and a strong dose-response relation was present. This association could not be explained by maternal age, race, education, or cigarette smoking. These results suggest that curtailment of smoking and alcohol consumption during pregnancy, a measure already widely prescribed during pregnancy, may also be an effective means of preventing childhood febrile seizures.