Scientists at Duke University studied a national database of nearly 17 million women pregnant between 2000 and 2003. A total of 33,956 of the women were treated for migraines.
The results showed that women treated for migraines during pregnancy were 19 times more likely to suffer a stroke, five times more likely to have a heart attack and more than twice as likely to have heart disease, blood clots and other vascular problems.
Previous studies have linked migraine with stroke and heart disease in women, but study author Cheryl Bushnell said that this latest research "now supports the same association in women who are pregnant".
"Women with persistent migraine during pregnancy should be aware of their risk factors, such as high blood pressure, high cholesterol, diabetes, history of blood clots, heart disease, and prior stroke," she added.
Further research, Dr Bushnell concludes, is needed to "validate" the findings.
The study was presented at the American Academy of Neurology's 59th Annual Meeting in Boston.
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