Prenatal and perinatal antecedents of febrile seizures.

We examined prenatal and perinatal characteristics as possible risk factors for febrile seizures in a large pediatric population. Family history was among the few identified factors that made an important contribution to vulnerability to febrile seizures; however, no more than 6% of febrile seizures could be attributed to a characteristic of family history. Maternal illness, smoking history, and a few rare neonatal characteristics were associated with increases in risk. No complication of labor or delivery was an important risk factor for febrile seizures.