There's been a surge in the number of strokes being suffered by pregnant women and new mothers in the United States.
Researchers think it's because more of them are obese, and suffering from high blood pressure and heart disease.
They say there was an increase of more than 50 percent in the number of hospitalizations for pregnancy-related strokes and "mini strokes" over the course of about a decade starting in the mid-1990s.
The number of strokes -- about 6,300 in 2006 and 2007 -- is still small, considering that around 4 million babies are born each year in the U.S.
But a stroke prevention expert says pregnancy increases a woman's risk of a stroke because of the hormone and blood changes that occur -- and that if a woman starts out unhealthy, she doubles her risk of suffering a stroke during or right after her pregnancy.
The study is published in the American Heart Association journal Stroke.