The Risk for Future Cerebrovascular Disease in Pregnant Women With Moyamoya Disease: A Nationwide Population-Based Study in South Korea

Background: Physiologic changes during pregnancy affect the development of postpartum cerebrovascular disease (CVD) in women with Moyamoya disease (MMD). Due to the rare prevalence of MMD and large regional variations, large-scale studies on the risk of CVD after delivery have not been conducted. The aim of this study was to evaluate whether women with MMD have an increased risk of CVD after delivery. Methods: : Research data was collected from the National Health Insurance Claims Database of the Health Insurance Review and Assessment Service. Patients delivered in Korea from 2007 to 2014 were enrolled. We classified women as CVD if they were diagnosed with stroke and/or cerebral infarction and/or intracranial hemorrhage and/or subarachnoid hemorrhage between delivery and December 31, 2016. To evaluate adjusted hazard ratio for CVD in women with MMD, we used multivariate Cox proportional hazard regression. Results: : Among 3,611,216 Korean women who had delivery, 382 had Moyamoya disease. When compared to women without MMD, women with MMD had a higher prevalence of pregestational diabetes and chronic hypertension. Also, women with MMD had a significantly higher incidence of cesarean section, pregnancy-induced hypertension, and gestational diabetes mellitus (p<0.0001, <0.0001, 0.02, respectively). Among women with MMD, a total of 246(64.4%) women developed CVD within the follow-up postpartum period, and 87.8% occurred within 2 years of postpartum. Women with MMD were associated with an increased risk of CVD in later (adjusted HR 108.24; 95% CI, 95.37-122.86) after adjusting for maternal age, parity, pregnancy-induced hypertension, gestational diabetes mellitus, pregestational diabetes, chronic hypertension. Conclusion: Our study showed that the incidence of CVD after delivery was higher in women with MMD. Therefore, we have to have more cautions of women with MMD and provide long-term postpartum surveillance