MONDAY, Aug. 24, 2020 (American Heart Association News) -- Pregnant women with preeclampsia are far more likely to develop heart failure later in life than those who don't have blood pressure-related pregnancy complications, especially if it occurs during more than one pregnancy, new research finds.
The study of more than half a million Norwegian women, published Monday in American Heart Association journal Hypertension, found those who developed preeclampsia during a single lifetime pregnancy were twice as likely to later have heart failure. Those who developed preeclampsia in more than one pregnancy were four times as likely. The women had their first birth between 1980 and 2004, and were followed through 2009.
The findings add to a growing body of research showing a relationship between a woman's reproductive phase of life and her long-term health, especially her cardiovascular risk, said the study's lead author Dr. Michael Honigberg, a cardiologist and researcher at Massachusetts General Hospital and Harvard Medical School in Boston.
"We, and others, have shown that women with pregnancy complications associated with high blood pressure get heart failure at higher rates later in life. That risk starts pretty early on and seems to persist at least into midlife," he said. "Now, we need to understand why this happens, from a biological standpoint, to know what to do to prevent it."
High blood pressure is common among pregnant women and, if it is not kept under control, can lead to numerous complications, including the need to induce labor, pre-term delivery, stroke, seizures or coma for the mother. Preeclampsia is characterized by high blood pressure and can include signs of liver or kidney damage during pregnancy, usually starting around the 20th week. It affects 1 in 25 pregnancies in the United States and can be harmful to mother and baby.
Whether blood pressure-related complications during pregnancy damage the mother's heart or simply unmask a predisposition to cardiovascular disease remains to be determined.
"It's possible that both of those things are true," said Honigberg, adding that another study he is involved with, published recently in the AHA's journal Circulation, found women with preeclampsia have a genetic predisposition to chronic high blood pressure as well as to obesity.
One thing Honigberg's new study does not address is how blood pressure-related pregnancy complications affect Black women, who are at greater risk for heart and pregnancy problems overall, said Dr. Melinda Davis, assistant professor of cardiovascular medicine and part of a maternal heart team at the University of Michigan in Ann Arbor.
Black women are 60% more likely to have high blood pressure than white women and are three to four times more likely to die from pregnancy-related complications.
Davis noted that Honigberg's study took place in Europe, where there also are different economic conditions and fewer gaps in health coverage than in the United States.
"It's likely that here we may see higher rates of hypertension and heart failure, particularly among women of color," Davis said. "Access to care, combined with socioeconomic limitations, are really important as health determinants.
"I think we definitely need more research on racially diverse populations," she said.
Pregnant women, and all women, should pay attention to their blood pressure and cholesterol levels and know their family history of heart disease, Davis said. "They need to be aware of these things and be sure they are being treated appropriately."
And, Honigberg said, if women do develop blood pressure-related complications during pregnancy, they need to tell their health care providers later in life.
"Very few primary care providers, or cardiologists, ask women about their pregnancy histories," he said. "This study implies that it's really critical that that change. We need to incorporate a woman's pregnancy history into our assessment of her cardiovascular disease risk."