Patient selection, flow diagram
88,857 patients were admitted to hospitals in New York State between 2003 and 2012 with preeclampsia. Of these, 197 individual women had preeclampsia and stroke. Strokes were classified as postpartum if they occurred either during a postpartum admission, or during a delivery admission that included a pregnancy-specific stroke code with a fifth digit of 2 or 4 indicating a postpartum complication, in accordance with ICD-9 coding guidelines.12 If the pregnancy-specific stroke code had a fifth digit of 3 indicating an antepartum complication, and the admission included a delivery, the stroke was categorized as antepartum. PEC: preeclampsia.