Feb. 6 (HealthDay News) -- High blood pressure during pregnancy is a warning sign of diabetes and heart disease later in life, a Dutch study indicates.

The study of 491 older, postmenopausal women found that those who had reported high blood pressure during a pregnancy had a 57 percent higher risk of developing calcium buildup in their arteries, compared with those whose blood pressure did not rise abnormally during pregnancy.

The findings were published online in the Feb. 5 issue of the journal Hypertension.

Calcification of the arteries is a marker of atherosclerosis or "hardening of the arteries," which is associated with an increased risk of cardiovascular disease.

"Our research and that of others may have important implications for the management of women who have high blood pressure in pregnancy," senior researcher Dr. Michiel L. Bots, associate professor of epidemiology at the Julius Center for Health Sciences and Primary Care in Utrecht, said in a statement.

The findings probably do not have implications for obstetric care, added Dr. Sharonne Hayes, director of the women's heart clinic at the Mayo Clinic in Rochester, Minn.

"We would still need to treat those women the same way as we now do during pregnancy," she said. "But now, those women have been marked as having an increased risk of heart disease. They have another marker of risk and need to be much more vigilant in looking for cardiovascular disease."

Previous studies have led to "a growing recognition that complications, and particularly cardiovascular complications, during pregnancy lead to an increased risk of heart disease later on," said Hayes, who is chair of the scientific advisory board of Women Heart: A National Coalition for Women With Heart Disease.

"As far as I know, this is the first to look at coronary calcification, which is a very good marker for the presence of cardiovascular disease," she said.

The U.S. National Heart, Lung and Blood Institute estimates that 6 percent to 8 percent of American women develop unusually high blood pressure during pregnancy. Some go on to develop a condition called preeclampsia, which can damage the placenta, kidney, liver and brain. A more serious condition, called eclampsia, is a leading cause of pregnancy-related mortality.

The increase in calcification in the Dutch study was seen not only in women who developed preeclampsia but also those with high blood pressure, Hayes noted.

"It is a sign that you need to be more careful about your risk of heart disease down the road," she said.

The women themselves and their physicians should be aware of their increased risk, said Dr. Daniel Jones, dean of the University of Mississippi School of Medicine and president-elect of the American Heart Association.

"In women who have had hypertension during pregnancy, there needs to be careful monitoring of cardiovascular risk factors, to [help them] be prepared appropriately to manage those factors," Jones said. "These women should be doing what we all should be doing -- keeping their weight in a good range, exercising, not smoking, eating a diet high in fresh fruits and vegetables."

The study, he said, "is a new way of looking at an issue that we have long suspected is a problem: that women who have hypertension in pregnancy are more likely to develop hypertension later in life, and hypertension is a known risk of vascular disease."