It’s possible that Black women have a higher heart failure risk than white women in this study because women of color often have higher rates of so-called cardiometabolic risk factors that can lead to heart failure such as diabetes and obesity, says Jennifer Stuart, ScD, an epidemiologist in the division of women’s health at Brigham and Women’s Hospital and Harvard Medical School in Boston. “The higher cardiometabolic burden carried by women of color likely results from a combination of lifestyle factors, such as diet and physical activity, as well as societal factors, such as access to quality care and the physiologic toll of systemic racism and other trauma,” says Dr. Stuart, who wasn’t involved in the study. Heart failure can happen when the heart muscle weakens, impairing the capacity to pump blood, or when the muscle stiffens, reducing its ability to relax as it fills with blood. Symptoms can include fatigue, swelling in the legs, shortness of breath, and difficulty exercising. For the study, researchers examined data on more than 425,000 women who gave birth in South Carolina from 2004 to 2016 and were followed through 2017. While the majority of women were white, 32 percent of them were Black. Almost 82 percent of the women in the study had normal blood pressure both before and during pregnancy; only about 2 percent of them had hypertension both before and during pregnancy. About 16 percent of the women in the study had normal blood pressure prior to conception but developed hypertensive disorders during pregnancy. Among this group, Black women had an 8.5-fold greater risk of heart failure within five years of delivery, compared with about a fourfold increased risk for white women.
Limitations of the Study
One limitation of the study is that researchers lacked data on what type of hypertensive disorders of pregnancy women developed — including whether they had the most severe and potentially life-threatening form known as preeclampsia. Researchers also lacked data on when during pregnancy hypertensive disorders developed or how long they persisted. Another limitation is that researchers lacked data on many social determinants of health that might impact pregnancy outcomes and heart failure risk, including the accessibility and affordability of care and experiences of systemic racism, says lead study author Angela Malek, PhD, an assistant professor in the department of public health sciences at the Medical University of South Carolina in Charleston. “These and other factors are important for future studies to investigate,” Dr. Malek says.
Earlier Research Links Pregnancy Hypertension to Heart Issues
Hypertensive disorders of pregnancy have previously been linked variety of heart conditions long after women give birth. One study published in July 2019 in the Australasian Journal of Ultrasound Medicine reviewed 23 previously published papers examining the long-term cardiac effects of preeclampsia. One in four women developed heart failure within 4 to 10 years of delivery. Roughly 1 in 5 developed a precursor to heart failure known as diastolic dysfunction, when the heart doesn’t fill with blood properly. Another study, published in October 2015 in Hypertension, followed more than 22,000 women starting in their mid-fifties, more than two decades after most of them delivered babies. The women who developed high blood pressure during pregnancy were more than twice as likely to have hypertension in middle age. A study published in August 2018 in the Annals of Internal Medicine followed almost 59,000 women without a history of cardiovascular disease for at least 25 years after their first delivery. People who developed hypertension during pregnancy were almost 3 times more likely to have this condition again by the end of the study period, and those who had preeclampsia had a more than doubled risk of hypertension down the line. Hypertensive disorders of pregnancy were also associated with an increased risk of developing diabetes and high cholesterol years later.
Reducing Your Risk
“Women can reduce their risk of developing hypertension before or during pregnancy by adhering to healthy lifestyle habits, including achieving or maintaining a normal body weight, not smoking, engaging in regular exercise, and eating a heart healthy diet,” Stuart says. All of these things can also help reduce women’s risk of developing heart failure. When women have a history of hypertension before or during pregnancy, they will need close monitoring for several years after delivery, Malek says. They need to be especially vigilant if they develop high blood pressure again or other risk factors for heart failure, including high cholesterol or obesity, Malek says, and take medication and make lifestyle changes recommended by their doctor. “Women with a history of hypertensive disorders of pregnancy may especially benefit from adopting a heart healthy diet and lifestyle as well as from more regular blood pressure screening after pregnancy to monitor and possibly reduce their risk of chronic hypertension, heart failure, and other adverse cardiovascular outcomes across their lives,” Stuart says.
