Risk of epilepsy in offspring of affected women: association with maternal spontaneous abortion.

BACKGROUND Previously, the authors found that risk of spontaneous abortion was increased in the pregnancies of women with epilepsy compared with their same-sex siblings, which could have implications for risk of epilepsy in their offspring. An association between a history of spontaneous abortion in the mother and risk of epilepsy in her live-born offspring may arise through selective loss of fetuses with a genetic susceptibility to epilepsy or through intrauterine environmental factors that may predispose the mother to a spontaneous abortion and to epilepsy in her live-born children. METHOD The authors examined the relation of a history of spontaneous abortion to the risk of idiopathic or cryptogenic epilepsy in 791 live-born offspring of 385 women with cryptogenic localization-related epilepsy (probands) ascertained from voluntary organizations. A semistructured telephone interview with probands and additional family informants, supplemented by medical record review, was used to obtain information on seizures and other risk factors in probands and relatives. RESULTS Live-born offspring of women with a history of spontaneous abortion were four or five times as likely to develop epilepsy as were children of women without (12.8% versus 4.7%; rate ratio = 4.6, 95% CI: 2.3-9.0). Cumulative incidence of epilepsy was 21.9% in offspring of women with a history of spontaneous abortion and a family history of epilepsy, compared with 4.7% in offspring of women with neither risk factor. CONCLUSIONS These results suggest that a history of spontaneous abortion is associated with increased risk of epilepsy in live-born offspring and may be a marker for genetic susceptibility for epilepsy in the mother.