In the study of nearly 2 million children, the vast majority of those born to moms with rheumatoid arthritis did not develop epilepsy, said lead researcher Ane Lilleore Rom, of Copenhagen University Hospital in Denmark.
Still, she said, the findings raise the possibility that when a woman has rheumatoid arthritis, conditions in the womb might make the fetal brain more vulnerable to epilepsy later on.
Rheumatoid arthritis is an autoimmune disease in which the immune system mistakenly creates antibodies that attack the lining of the joints. Epilepsy, meanwhile, is a seizure disorder caused by disrupted electrical activity in the brain.
In theory, “autoimmune factors” in the womb — such as those self-attacking antibodies — might make some children more prone to epilepsy, Rom speculated.