Ischemic cerebrovascular complications of pregnancy.

Pregnancy increases the risk of focal ischemic cerebrovascular events, apparently to about 13 times the expected rate outside of pregnancy in the case of cerebral infarction. The distribution of the underlying pathophysiologic mechanisms causing the cerebrovascular symptoms in pregnant patients differs considerably from the distribution in the general population. Although most focal ischemic lesions that occur during pregnancy seem to be the result of arterial occlusion, cerebral venous thrombosis is still a prominent factor in causing such lesions. Arterial occlusions tend to occur during the second and third trimesters of pregnancy and during the first week after delivery, whereas the venous occlusions tend to occur one to four weeks after childbirth. When possible, treatment of patients with focal ischemic neurologic symptoms is based on a precise definition of the underlying pathophysiologic mechanism and its appropriate treatment. When this is not possible, patients are treated according to categorization based on the temporal profile of the focal deficit.