There has been a significant increase in women's rate of stroke during their pregnancy, according to a new study published on Thursday in Journal of the American Heart Association.

The data was collected from a huge national database of 5 to 8 million discharges from 1,000 hospitals. The study compared the rates of strokes from 1994-1995 and 2006-2007 in women who were pregnant.

The study discovered that the rate of stroke-related hospitalizations increased by 47 percent. For pregnant women and women in the post-partum stage, it surged 83 percent.

The study found pregnant and post partum women ages 25 to 34 were hospitalized for stroke more frequently than those who were younger or older.

"I am surprised at the magnitude of the increase, which is substantial," said Elena V. Kuklina, M.D., Ph.D., lead author of the study and a CDC epidemiologist.

"When you're relatively healthy, your stroke risk is not that high," Kuklina said. "Now more and more women entering pregnancy already have some type of risk factor for stroke, such as obesity, chronic hypertension, diabetes or congenital heart disease. Since pregnancy by itself is a risk factor, if you have one of these other stroke risk factors, it doubles the risk."

Kuklina said doctors lack guidance in the area because pregnant women are frequently excluded from clinical trials due to the potential harm of the drugs to harm the fetus.

She suggested developing a comprehensive, multidisciplinary plan that provides doctors and patients guidelines for good monitoring and care before, during and after childbirth.

"We need to do more research on pregnant women specifically," said Kuklina, who discovered only 11 cases of pregnancy-related stroke in her review of previously published literature.