Prenatal and perinatal antecedents of febrile convulsions and afebrile seizures: data from a national cohort study.

The assumption is often made that brain damage during the perinatal period is likely to result in neurological abnormalities such as epilepsy and cerebral palsy. However, there has been accumulating evidence that cerebral palsy is rarely, if ever, a result of intrapartum events, but few studies of other neurological abnormalities have been undertaken. We analysed data on 16,163 children from the 1970 British national cohort study and followed to age 10, focusing on the 378 who developed febrile convulsions (FCs) and 63 children with idiopathic afebrile seizures (IAS). Children with IAS were significantly more likely not to have been breast fed (P < 0.001), and this was independent of features such as birthweight and maternal disorder. A similar finding was apparent for FCs (P < 0.05). Although children with low birthweight were at increased risk of both conditions, there was no association with maternal smoking in pregnancy. No associations were found between indications of fetal distress during labour and later febrile convulsions or afebrile seizures. There was no evidence that intervention during labour would have improved these outcomes. However, associations were found with abnormalities earlier in pregnancy, suggesting a prenatal rather than an intrapartum aetiology.