Children born to mothers with rheumatoid arthritis (RA) are more likely to develop epilepsy, according to a Danish study.
Researchers followed approximately 1.9m singletons for a mean of 16 years. They stratified the 31,491 children with epilepsy depending on age on onset: early childhood (29 days to four years), late childhood (five to 15 years), and adolescence and adulthood (at least 15 years). Children whose mothers did not have RA acted as controls.
Paternal RA was not associated with epilepsy but children whose mothers had RA were 34 per cent more likely to show epilepsy in early childhood than controls. The risk of epilepsy in late childhood was 26 per cent higher. The 15 per cent increase in adolescence and adulthood was not statistically significant.
Children exposed to maternal RA in utero were more likely to show early childhood epilepsy than those with mothers diagnosed after childbirth: 90 and 26 per cent increase respectively. (Women diagnosed after birth probably had preclinical RA during pregnancy.) The increases in late childhood epilepsy were 35 and 27 per cent respectively; the latter was statistically significant.
Alterations in the intrauterine environment may contribute to the association, the authors suggest. The mechanism is unknown, although maternal antibodies, inflammatory cytokines and chemokines, or vascular complications, may contribute.