Risk of ischemic stroke during pregnancy and postpartum period in women with a prior history of ischemic stroke

BACKGROUND: The risk of recurrent ischemic stroke during pregnancy or postpartum period in women with a history of ischemic stroke is unclear. AIMS: To determine the risk of incident ischemic stroke during pregnancy or early postpartum period (within 6 weeks) among women with and without a prior history of ischemic stroke. METHODS: (ICD-10-CM) I69.3x/Z86.73; and incident ischemic stroke by I63 during pregnancy or ⩽ 42 days postpartum. Odds ratios (ORs) with 95% CIs were estimated using multivariable logistic regression after 1:10 propensity-score matching based on demographics and comorbidities. RESULTS: The incident ischemic stroke rates were 415 out of 1192 pregnancies (34.82%, 95% confidence interval [CI] = 32.16%-37.56%) among pregnant women with a prior history of ischemic stroke and 737 out of 219,287 pregnancies (0.34%, 95% CI = 0.31%-0.36%) among pregnant women without a history of ischemic stroke. In the multivariate analysis, the risk of ischemic stroke during pregnancy or early postpartum period was significantly higher among pregnancies in women with a prior history of ischemic stroke compared with those in women without a history of ischemic stroke (OR = 2.37, 95% CI = 1.97-2.87, p < 0.0001). Previous myocardial infarction (OR = 1.82, 95% CI = 1.38-2.39, p < 0.0001) and obesity (OR = 1.25, 95% CI = 1.07-1.47, p < 0.01) were also associated with recurrent ischemic stroke during pregnancy or early postpartum period. The odds of experiencing an incident ischemic stroke among women with a prior history of ischemic stroke was significantly higher in women during pregnancy or early postpartum period compared with those with neither of the two conditions (OR = 3.35, 95% CI = 2.67-4.22, p < 0.0001). CONCLUSION: Women with a prior history of ischemic stroke had two times higher odds of having another ischemic stroke during pregnancy or postpartum period. Our findings have implications for counseling, surveillance, and enhanced recurrent stroke prevention in this high-risk group.