Incidence and Risk Factors for Stroke in Pregnancy and the Puerperium

Pregnancy-related stroke is rare, but it can be a devastating event. Apart from mortality estimates of 8% to 15%, survivors may have marked and permanent disability. The authors reviewed data from the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality for the years 2000–2001, seeking cases of stroke among pregnancy-related discharges. The goal was to determine the incidence of, risk factors for, and disability and mortality resulting from pregnancy-related stroke in the United States during the period under review. Pregnancy-related discharges with a diagnosis of stroke totalled 2850, equivalent to 34 per 100,000 deliveries in this group of more than 9 million discharges. The 117 stroke-related deaths represented a mortality risk of 1.4 per 100,000. Nearly half the strokes (48%) occurred in the postpartum period, 11% were antepartum, and 41% took place at the time of delivery. Ischemic stroke accounted for 27% of cases, hemorrhagic stroke for 25%, pregnancy-related cerebrovascular events for 46%, and cerebral venous thrombosis for 2%. In general, the risk of stroke increased with age, but it was higher in women less than 20 years of age than in those aged 20–34 years. For women aged 35–39 years, the risk increased markedly. Black women had a higher risk of stroke than did Hispanic or white women. The stroke risk was highest for black women who were 35 or more years of age. The odds ratio (OR) for women 35 and older, compared with younger women, was 2.2, and that for black women aged 35 and older was 4.5. The strongest medical associations with stroke were migraine headaches (OR, 16.9), thrombophilia (OR, 16.0), lupus (OR, 15.2), heart disease (OR, 13.2), and sickle cell disease (OR, 9.1). Less marked but still significant associations were with hypertension, thrombocytopenia, diabetes, substance abuse, smoking, and anemia. Complications that correlated significantly with pregnancy-related stroke were pregnancy-related infection (OR, 25.0), transfusion (OR, 10.3), fluid and electrolyte imbalance (OR, 7.2), preeclampsia and gestational hypertension (OR, 4.4), and postpartum hemorrhage (OR, 1.8).