High blood pressure during pregnancy puts moms at a significant risk for cardiovascular disease later in life. But in a new study that looked back more than three decades, researchers found that a type of hypertension during pregnancy that causes only a temporary hike in blood pressure may be especially hazardous to the heart.

The study, released Monday in the journal Hypertension, analyzed the medical records of more than 1,000 women in Sydney, Australia, who had either normal blood pressure or high blood pressure during their pregnancies in the 1980s.

Women with any form of hypertension during pregnancy were nearly three times as likely to later develop chronic high blood pressure or kidney disease. They were also twice as likely to develop heart disease or have a stroke later in life.

The finding wasn’t unexpected, given that previous research has already confirmed the link between long-term heart health and hypertension during pregnancy. But this new study dug deeper, comparing future cardiovascular disease risk between women with various types, degrees and treatments of high blood pressure during pregnancy.

Surprisingly, women with gestational hypertension were more likely to develop future hypertension and heart disease than women with preeclampsia—a pregnancy syndrome that can damage organs such as the liver and kidneys and is considered much more dangerous.

“The take-home message is that gestational hypertension is just as significant a predictor of future cardiovascular risk as preeclampsia,” said Monique Chireau, M.D., an obstetrician and assistant professor at Duke University who was not involved in the study.

That means doctors should take gestational hypertension just as seriously as preeclampsia and consider obstetric history when assessing a woman’s cardiovascular health, the study authors noted.

“Women who develop any of these [forms of hypertension], though, need to follow up with their primary care doctor,” Chireau said. Other forms include chronic hypertension that existed before pregnancy and chronic hypertension with superimposed preeclampsia, meaning women with preexisting high blood pressure who also develop preeclampsia.

But medical follow-ups are easier said than done, the obstetrician admitted.

“Most women are very good at being seen during pregnancy with their prenatal visits, but after that they often don’t really engage much with the medical system. They’re perceived as being healthy young women, and while they are raising their children, they’re just too busy,” Chireau said.

The study researchers also emphasized the importance of women following up with their doctors. “These women need life-long close monitoring of blood pressure and cardiovascular disease,” they wrote.

Taking high blood pressure medication during pregnancy didn’t make a difference in a woman’s risk of future cardiovascular disease, according to the study. The length of time a woman had high blood pressure while pregnant also had no effect.

In the United States alone, high blood pressure affects 6 percent to 8 percent of pregnancies. So what can pregnant women do to reduce their chances of developing high blood pressure?

“That is the unanswered question,” Chireau said.

She noted there is a body of research showing that aspirin can prevent preeclampsia in high-risk women, but there is considerable variation between studies regarding the appropriate dosage of aspirin and when to start it in pregnancy to reduce preeclampsia risk.

“So it’s still not well understood how to prevent the development of high blood pressure while pregnant,” Chireau said.

But, she added, perhaps the most important thing women can do is to be at a healthy weight when they get pregnant and avoid excess weight gain in pregnancy. Preconception counseling is also important so that moms-to-be can be screened for chronic hypertension, diabetes and other health problems before getting pregnant.

More proven and specific cardiovascular prevention strategies for moms remain to be determined.