Hypertensive Disorders of Pregnancy-related Stroke: Incidence, Trends, Risk Factors, and Outcomes in the Nationwide Inpatient Sample

Abstract Number: O1-02
Abstract Type: Original Research

Introduction: Despite the fact that stroke is one of the most feared complications of hypertensive disorders of pregnancy (HDP) (1,2), there is a dearth of literature examining the prevalence, etiologies, risk factors, and outcomes of hypertension-related stroke in pregnancy.

Methods: Using the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality, we extracted all pregnancy hospitalizations of women aged >15-44 years from 1994-2011 (N=81,983,217). Stroke hospitalizations (N =31,673) and their comorbidities were identified by the International Classification of Diseases, 9th edition (ICD-9 CM) codes. All statistical analyses accounted for the complex sampling design of the data source. Odds ratios (OR) with 95% confidence intervals (95% CI) for stroke were obtained using logistic regression analysis after adjustment for study period, age, payer, hospital teaching status, region, and delivery mode.

Results: Between 1994-1995 and 2010-2011, the nationwide rates of pregnancy related stroke with HDP increased by 102.6% (from 0.8 to 1.6 per 10,000 pregnancy hospitalizations) while the rate of pregnancy related stroke without HDP increased by 46.6% (from 2.2 to 3.2 per 10,000 pregnancy hospitalizations). Compared to women without HDP, women with HDP were about 5.2 (95% CI: 4.9-5.6) times more likely to have stroke. Systemic lupus erythematosus, primary thrombocytopenia, congenital coagulation defects, sickle cell anemia , atrial fibrillation, and valve disorders were all independent RF for stroke (OR ranged from 2.3 (95% CI: 1.7-3.0) for sickle cell anemia to 19.4 (95% CI: 12.2-30.8) for atrial fibrillation), and when coupled with HDP showed a markedly elevated risk for stroke (OR ranged from 11.6 (95% CI:8.0-16.8) for congenital coagulation defects to 37.6 (95% CI: 19.7-71.9) for atrial fibrillation). Stroke-related complications, including the need for mechanical ventilation, seizures, pneumonia, prolonged hospital stay and death during hospitalization were increased in women with HDP-related stroke compared to women with non-HDP-related stroke, with OR ranging from 1.2 (95% CI: 1.1-1.4) for prolonged hospital stay to 1.9 (95% CI: 1.6-2.3) for mechanical ventilation.

Conclusion: Having specific traditional stroke risk factors substantially increases the risk of stroke in women with HDP. Compared with non-HDP-related stroke, HDP-related stroke has two distinctive characteristics: a greater increase in prevalence since the mid-1990s (3) and significantly higher rates of stroke-related complications.

(1) Obstet Gynecol, 2009; 113:1299-306. (2) Women’s Health, 2011; 7:363-74. (3) Stroke, 2011; 42:2564-70.

SOAP 2014