Pregnancy, Hormonal Contraception, and Postmenopausal Estrogen Replacement Therapy

Epidemiology

The reported incidence of stroke during pregnancy and the puerperium ranges from 4 to 34 per 100,000 deliveries or pregnancies . The US Nationwide Inpatient Sample (NIS; a 20% stratified sample of all discharges in the United States) identified 2850 pregnancies complicated by stroke in the years 2000–01, for a rate of 34.2 per 100,000 deliveries . The mortality rate was 1.4 per 100,000. Pregnancy-related intracerebral hemorrhage (ICH) was associated with the highest morbidity and mortality. Recent analysis of data from the NIS demonstrated that between 1994–95 and 2006–07, the rates of antenatal and postpartum hospitalizations for all types of strokes increased by 47% and 83%, respectively . This increase was thought to be related to the increase in hypertensive disorders, obesity, and heart disease.

The 6 weeks postpartum and, particularly, the several days around delivery are times of increased risk for ischemic and hemorrhagic stroke as well as for cerebral venous thrombosis (CVT) . A nationwide Swedish cohort study found that cerebral infarction was 33.8 times (95% CI: 10.5–84.0) more likely to develop in the 3 days surrounding delivery (defined as 1 day before and 2 days after delivery), and 8.3 times (95% CI: 4.4–14.8) more likely in the subsequent 6 weeks after delivery. Antenatally, the risk was negligible (OR, 2.2; 95% CI, 0.8–4) .