Preeclampsia Ups Heart Disease, Death

Nov. 1, 2007 -- Preeclampsia doubles a woman's risk of later heart disease -- perhaps over and above the risk from other factors that contribute to heart disease.

Preeclampsia is a pregnancy syndrome marked by dangerously high blood pressure. In the developed world, 3% to 5% of women develop preeclampsia during their first pregnancy.

During pregnancy, preeclampsia poses risks to both mother and child. But a woman's risk continues long after the child is born. Now a research team led by preeclampsia expert David Williams, MBBS, PhD, FRCP, University College London, calculates these risks.

"Women who have had preeclampsia have a twofold higher risk of heart disease, stroke, and thromboembolism [dangerous blood clots]," Williams tells WebMD.

Williams, medical student Leanne Bellamy, and colleagues analyzed 25 long-term studies of preeclampsia. Their data provided information on 3.5 million women, nearly 200,000 of whom had preeclampsia.

They found that women who had preeclampsia were:

• 2.16 times more likely to have heart disease within 11.7 years
• 1.81 times more likely to have a stoke within 10.4 years
• 1.79 times more likely to have venous thromboembolism (dangerous blood clots) within 4.7 years
• 1.49 times more likely to die within 14.5 years
• 3.7 times more likely to have high blood pressure within 14 years
• No more or less likely to have cancer within 17 years.

An editorial by Laura A. Magee, MD, FRCPC, clinical associate professor of medicine at the University of British Columbia, Canada, accompanies the Williams study.

"The bottom line is this is information women learn about themselves during pregnancy," Magee tells WebMD. "It should give them pause to do something -- to think about their risk and effect change."

Pregnancy as Stress Test

The study findings suggest that heart disease and preeclampsia share many of the same risk factors. But Williams says the data also suggest that the risk from preeclampsia may be independent -- that is, over and above risks such as being overweight or having high cholesterol.

"Is a history of preeclampsia an independent risk factor that adds to a woman's future cardiovascular risk? One of the biggest studies we looked at suggests it is an independent risk," Williams says. "So a middle-aged woman might have her cardiovascular risk calculated from classical risk factors. But if she has a history of preeclampsia, it could be up to a twofold additional risk."

Because many women are young when they give birth, they are at very low risk of having heart disease right away -- even if they have preeclampsia. But pregnancy gives a woman a look into a crystal ball that warns of coming trouble.

"Pregnancy acts as a physical stress test that temporarily draws out her high blood pressure," Williams says. "It goes away after she gives birth. But the woman must not forget she is at risk. If she remembers early enough, she can benefit from lowering her cardiovascular risk."