Demyelinating and neoplastic diseases in pregnancy.

Multiple sclerosis (MS) has no significant effect on fertility, conception, fetal viability, and delivery. Exacerbations of MS decrease during pregnancy and increase significantly during the 3 months postpartum. Pregnancy does not increase the risk of brain tumors, but physiologic changes induced by pregnancy affect the diagnosis and biologic behavior of glial tumors, meningiomas and vascular tumors, and pituitary adenomas. MR imaging and computed tomography scanning are the most useful modalities for diagnosis.