In one study in the United States, 7 percent of cerebral venous thromboses were associated with pregnancy (Wasay, 2008). But, in the Nationwide Inpatient Sample of more than 8 million deliveries, James and associates (2005) reported that venous thrombosis caused only 2 percent of pregnancy-related strokes (Saposnik, 2011). here are numerous predisposing causes, and for gravidas, late pregnancy and the puerperium are times of greatest risk.
Thrombosis of the lateral or superior sagittal venous sinus usually occurs in the puerperium and often in association with preeclampsia, sepsis, or thrombophilia (see Fig. 60-2). It is more common in patients with inherited thrombophilias or antiphospholipid antibodies (Chaps. 52, p. 1006 and 59, p. 1143). Headache is the most frequent presenting symptom, neurological deficits are common, and up to a third of patients have convulsions (Wasay, 2008). he diagnosis is made using MR venography (Saposnik, 2011).
Management includes anticonvulsants for seizures, and although heparinization is recommended by most, its eicacy is controversial (Saposnik, 2011; Smith, 2015). Antimicrobials are given if there is septic thrombophlebitis, and fibrinolytic therapy is reserved for those women failing systemic anticoagulation. The acute prognosis for venous thrombosis in pregnant women is better than in nonpregnant subjects, and mortality rates are less than 10 percent (McCaulley, 2011).
In women with a prior cerebral venous thrombosis, one systematic review found only one recurrence in 217 pregnancies and five noncerebral venous thrombotic events in 186 pregnancies (Aguiar de Sousa, 2016). In a study of 52 women on prophylactic anticoagulation with prior cerebral venous thrombosis, there were no cases of recurrent thrombosis or bleeding, however 24 percent had late obstetrical complications (Martinelli, 2016).
Recurrence Risk of Ischemic Stroke
Women with prior ischemic stroke have a low risk for recurrence during a subsequent pregnancy unless a specific, persistent cause is identiied. During a 5-year follow-up of 373 women with arterial ischemic strokes, there were 187 pregnancies in 125 women. Thirteen women had a recurrent ischemic stroke, and of these, only two were associated with pregnancy. The authors concluded that the risk of stroke recurrence is low and a previous ischemic stroke is not a contraindication to pregnancy (Lamy, 2000). In one study of 1770 nonpregnant women with anti phospholipid-related ischemic stroke, investigators reported no diference in the recurrence risk as long as preventative treatment was given with warfarin or aspirin (Levine, 2004).
Currently, no irm guidelines define prophylaxis in pregnant women with a stroke history (Helms, 2009). The American Heart Association stresses the importance of controlling risk factors such as hypertension and diabetes (Furie, 201l). Women with anti phospholipid syndrome or certain cardiac conditions should be considered for prophylactic anticoagulation as discussed in Chapter 49 (p. 954) and 52 (p. 1008).
The two distinct categories of spontaneous intracranial bleeding are intracerebral and subarachnoid hemorrhage. The symptoms of a hemorrhagic stroke are similar to those of an ischemic stroke, and their diferentiation is only possible with CT or MR imaging (Morgenstern, 2010; Smith, 2015).