The rate of stroke is rising in pregnant women and in women who have just given birth, according to new research by the Centers for Disease Control and Prevention.
Between 1994-95 and 2006-07, the percentage of expectant women who were hospitalized for stroke rose 47%, while the percentage of new mothers who suffered stroke in the three months after delivery increased 83%. The total number of hospitalizations for stroke increased 54% over that decade.
“It’s a little alarming,” says lead study author Elena Kuklina. “It reminds us we should strive to take good care [of ourselves] before and during pregnancy.”
The absolute number of strokes was still small, however, at 0.22 occurrences of stroke (up from 0.15) per 1,000 deliveries. Kuklina notes that stroke is a rare condition for women, but cautions that the findings suggest a particular risk among the study’s population. “[The results] still tell us stroke is getting kind of younger, and pregnant women are especially at risk,” she says.
Kuklina’s team looked at hospital discharge data for six types of stroke: subarachnoid hemorrhage, intracerebral hemorrhage, ischemic stroke, transient ischemic attack, cerebral venous thrombosis and unspecified stroke. The rise in stroke rates, they found, was strongly associated with the increasing likelihood that pregnant women had other risk factors for stroke, such as obesity, high blood pressure, heart disease and diabetes.
For instance, more women hospitalized for stroke after delivery had high blood pressure in 2006-07, compared with the earlier time period. In fact, high blood pressure and heart disease accounted for nearly all of the increased risk of hospitalization for stroke after birth.
What’s unclear is whether pregnancy alone would increase stroke risk in healthy women without other risk factors. “There is not enough information currently … to say that healthy pregnancy by itself will increase the risk of complication,” Kuklina says.
The authors acknowledge some limitations of their work: they could not determine, for example, whether women may have been hospitalized for stroke multiple times during the study period; that could have driven up the overall hospitalization rate. Further, their estimate of the number of stroke-related hospitalizations during the postpartum period may have been affected by the fact that they used diagnostic codes, rather than full medical record reviews, to identify stroke and other diseases.
Despite the caveats, Kuklina urges all women — whether pregnant or planning to become pregnant — to take measures to prevent the health problems commonly associated with stroke. Her recommendations are straightforward and familiar:
• Eat a low-fat, low-sodium, high-fiber diet
• Maintain a healthy weight
• Stay physically active
• Don’t smoke
Women suffering from chronic conditions like heart disease or diabetes should also begin treatment far in advance of pregnancy, Kuklina says. Even those carrying a little extra weight can be proactive by “dropping a few pounds before pregnancy,” she says. Given that “any person who has had stroke has increased risk of repeat stroke,” Kuklina says, women would be wise to follow her guidelines for better long-term health.
The study was published in Stroke: Journal of the American Heart Association.