Statistical methods
The basic characteristics between the two study groups were compared by Chi-square test. We used a Cox regression model to compare the adjusted hazard ratio (aHR) and 95% confidence interval (CI) for stroke occurrence. Cumulative incidence functions for the first occurrence of stroke episode between pre-eclampsia/eclampsia and non-pre-eclampsia/eclampsia women were compared using the Kaplan–Meier model. The SAS software (version 9.2; SAS Institute, Inc., Cary, NC) was used for all statistical analyses. A two-sided P -value of <0.05 was considered statistically significant.