NEW ORLEANS — The risk of stroke among more than 8 million American women during the pre-, peri-, and postpartum periods was 34/100,000, a higher rate than previously calculated.
In addition, the risk of stroke rises with age. Women who were at least 40 years old had a 3.3-fold increased risk of stroke during pregnancy, delivery, and immediately after delivery, compared with women 15-19 years old, Cheryl D. Bushnell, M.D., reported at the 30th International Stroke Conference.
Women 35-39 years old had a 90% increased risk, compared with women younger than 20, said Dr. Bushnell, a neurologist at Duke University in Durham, N.C.
Although the stroke risk during pregnancy and delivery was higher than previous estimates of 4-26/100,000, there are currently no clear implications of what this finding means for monitoring and managing women during pregnancy and delivery, commented Andra H. James, M.D., an obstetrician at Duke and a coinvestigator on this study. Dr. James had no recommendations for changing current obstetric practice based on the new finding.
The researchers used data collected in the Nationwide Inpatient Sample during 2001-2002. This database, maintained by the Agency for Healthcare Research and Quality, is a 20% sample of all inpatients at about 1,000 community hospitals in the United States.
The database included records for more than 8 million women who were discharged with prepartum, delivery, or postpartum codes. In this group, 2,850 women had a stroke, a rate of 34.2 events/100,000 women, Dr. Bushnell said at the conference, sponsored by the American Stroke Association.
Besides age, race was a variable that affected women's stroke risk. African American women had a 70% increased risk, compared with white women. Clinical factors that boosted the risk of stroke were preeclampsia, postpartum infection, a blood transfusion, and any other comorbidity.
Of the 2,850 women with strokes, 117 died, for a mortality of 4.1%. and a rate of 1.4 stroke deaths per 100,000 deliveries. Given that the overall mortality rate during pregnancy and delivery in the United States is 10/100,000 deliveries, stroke accounts for 14% of all maternal deaths, Dr. Bushnell said.