MS tends to affect women of childbearing age. Women with MS may have concerns about both the effect of pregnancy on the course of MS and the effect of MS on the course of pregnancy. Current evidence suggests that pregnancy causes a reduction in relapse rate, especially during the third trimester, with a subsequent increase in relapse rate immediately postpartum. However, there is no evidence that pregnancy has long-term detrimental effects on the course of MS. Women with MS appear to have similar experiences with pregnancy to those of women without MS, with the possible exception of an increased need for assistance with infant care during the postpartum period. Preliminary data suggest that immunomodulators (particularly glatiramer acetate) may be safe during pregnancy, but that the immunosuppressant mitoxantrone should not be used. The use of IVIG to prevent the increase in relapse rate seen in the puerperium is being investigated. Neurologists should familiarize themselves with information about pregnancy and MS, so that they may provide accurate information for their patients with MS who are pregnant or contemplating pregnancy.