Women who develop a dangerous elevation in blood pressure during pregnancy may develop thickened heart tissue soon after delivery, a new study shows.

In the study, women with preeclampsia had an increased risk of left ventricular hypertrophy one month after delivery compared to pregnant women without preeclampsia. The heart problem occurs when the left pumping chamber thickens, making it more difficult for the heart to pump efficiently.

The findings were presented Thursday at the American Heart Association and American Society of Hypertension Joint Scientific Sessions in San Francisco.

The researchers also found that the heart changes were more severe in women who developed preeclampsia before the 34th week of pregnancy.

“Women with early-onset preeclampsia have the greatest risk to develop cardiovascular disease later in life,” said study researcher GianLuca Colussi, M.D., an assistant professor of medicine at the University of Udine in Italy.

None of the women in the study had high blood pressure before getting pregnant. An estimated 2 percent to 8 percent of all pregnancies globally and about 3.4 percent in the United States result in preeclampsia, according to the National Institutes of Health.

Colussi said more research is needed to confirm the results and to figure out why the heart changes are more likely to occur. But for now, he said, women with preeclampsia should be screened for cardiovascular risk factors and prevention strategies should be implemented as soon as possible.

“We’ve shown that women with early-onset preeclampsia might be at even greater risk, suggesting preventive interventions, such as using medications that act on left ventricular remodeling,” he said.