Mechanisms and outcomes of stroke during pregnancy and the postpartum period A cross-sectional study

Background: Pregnancy-associated stroke remains incompletely characterized because of the rarity of these potentially devastating events. We investigated whether mechanism and outcome of ischemic pathophysiology stroke differ between young pregnant and nonpregnant women. Methods: We identified 135 consecutive women ages 18-40 years admitted to our center from January 2008 through June 2014 with ischemic stroke, TIA, cerebral venous thrombosis, or nonaneurysmal subarachnoid hemorrhage due to reversible cerebral vasoconstriction syndrome (RCVS). We reviewed charts for pregnancy status, demographics, medical comorbidities, stroke severity, etiology, and discharge outcomes. Results: There were 33 women with pregnancy-associated stroke (PAS) and 102 with non-pregnancy-associated stroke (NPAS). Among women with PAS, 73% of strokes occurred postpartum. In the PAS group, the most common cause of cerebrovascular events was RCVS (n = 12), 11 postpartum and 4 in women with preeclampsia. There were no significant differences between the groups in demographics. Women with PAS were less likely to have vascular risk factors such as hyperlipidemia and history of thromboembolism but more likely to have cerebral venous thromboses (21% vs 7%, p = 0.02). Women with PAS were more likely to have RCVS as stroke mechanism (36% vs 1%, odds ratio 57.7, 95% confidence interval 7-468, p = 0.0001). Conclusion: Compared with nonpregnant women of the same age group, women with PAS had fewer vascular risk factors. Cerebral venous thrombosis and RCVS were more common in PAS, most of which occurred postpartum. These results provide further evidence for the unique pathophysiology of pregnancy-related stroke, raising important questions for future investigation.