Oral contraceptives and the risk of multiple sclerosis: a review of the epidemiologic evidence.

Multiple sclerosis (MS) is more frequent in women than in men, suggesting that sex hormones could play a role in the development of MS. For this reason, several studies have assessed whether use of oral contraceptives modifies the risk of MS. In this article, we review the methodology and results of published epidemiologic studies addressing this issue. On the whole, the existing epidemiologic evidence does not support an important effect of oral contraceptive use on the risk of MS, though it does suggest that oral contraceptives might delay the onset of the disease.