New information out of an Australian research facility is cautioning pregnant women that any kind of hypertensive disorder of pregnancy during their term could result in cardiovascular complications in the future.

The link between hypertension during pregnancy and increased risk of future cardiovascular disease (CVD) isn’t new, lead researcher Jane Tooher and co-authors wrote in a recent study, which was published in Hypertension's October issue. It’s well-documented that women who experience hypertensive disorders of pregnancy (HDP) are at an increased risk for future heart problems when compared to a similar, normotensive group, and 5 to 10 percent of all pregnancies worldwide are affected by HDP. However, Tooher’s team wanted to look into the possible connections between future CVD risk and all forms of hypertensive disorders of pregnancy, factoring in maximum blood pressure, use of antihypertensive medication and duration of disease, according to the research.

In the broadest component of their study, Tooher and co-authors used medical records from more than 30,000 women admitted to an Australian hospital between 1980 and 1989 and retrospectively analyzed their pregnancies.

Of the large group, 86.2 percent of mothers remained normotensive in their pregnancies, while 13.8 percent were diagnosed with HDP at some point during the nine months. After narrowing the subjects to a randomized cohort of under 500, Tooher’s team found 34 percent of those women developed severe hypertension during their pregnancies, and mothers with high blood pressure were almost three times more likely to develop chronic hypertension or kidney disease in the future. They were also twice as likely to suffer from a heart attack or stroke.

HDP is split into four categories—preeclampsia, gestational hypertension, chronic hypertension and preeclampsia superimposed with hypertension—with preeclampsia considered the most dangerous disorder.

Still, although preeclampsia might be regarded as the most dangerous subset of HDP, Tooher’s study revealed that women diagnosed with gestational hypertension were more likely than those diagnosed with preeclampsia to develop serious hypertension in the future. While Tooher and co-authors compared results of women who received antihypertensive medication during their pregnancies with those who did not, they found that medication had no bearing on future risk of CVD.

In a release from the American Heart Association, Monique Chireau, MD, an obstetrician who wasn’t involved in the study, said there isn’t a conclusive answer to the question of how to prevent hypertension during pregnancies. Aspirin, she said, has been shown to help, but doctors still aren’t sure of dosages and other important factors. Staying at a healthy weight while trying to conceive and going to preconception counseling for preemptive screenings could also be important factors.

Women should also follow up with their primary care doctors after giving birth, Chireau told AHA, which happens much less often than it should.

“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,” she said. “They’re perceived as being healthy young women, and while they are raising their children, they’re just too busy.”

Tooher’s study showed risk of future cardiovascular complications increased with the severity of HDP diagnoses. Also linked to increased risk of heart disease in the future was preterm delivery. Tooher noted in the study that more extensive research will be required to determine whether or not early identification and preventative measures have any bearing on risk of future CVD.

“These results indicate that a woman who experiences HDP should be monitored closely to identify early recognition of any CVD factors,” Tooher and co-authors wrote in the paper. “It is also important that both women and clinicians are well-informed of the increased risk of future CVD after a history of HDP.”