Pregnancy and multiple sclerosis.

Retrospective studies strongly suggest that pregnancy is an example of a naturally occurring human condition that consistently and predictably affects the course of multiple sclerosis (MS). Pregnancy seems to be associated with clinical MS stability or improvement, while the postpartum period seems to be one of high risk for clinical flares of the disease symptoms. Similarly, pregnancy protects animals from developing experimental allergic encephalomyelitis. Immune system changes in pregnancy and MS are reviewed, as they may be involved in the observed clinical effects of pregnancy on MS. Important questions of the patient with MS in the childbearing age group are addressed.