Pregnancy complications heighten heart risks in later life. It’s time to pay attention

The American Heart Association has released its 2023 Statistical Update and the results are grim: In 2020, the first year of the Covid-19 pandemic, more people died from cardiovascular-related causes than ever before: a staggering 928,741 deaths. While there are many causes of this increase, one is the increased burden that Covid-19 wrought on individuals’ bodies and entire systems.

A simultaneous epidemic is underway, and it is important to connect the dots between the two. While heart disease deaths are at a historic high, so too are disorders arising from high blood pressure (hypertension) during pregnancy, a problem that predated the pandemic. Between 2007 and 2019, high blood pressure in pregnancy, including preeclampsia — a disorder of elevated blood pressure and protein in the urine that can cause serious complications for pregnant people and their babies — doubled in the United States. In 2021, an estimated 475,000 people in the U.S. developed preeclampsia or gestational hypertension, a related disorder. In concert, the rate of maternal mortality in the U.S. has also been rising, with the U.S. having some of the worst maternal mortality rates among high-income countries globally.

Why connect these two epidemics? In addition to being a leading cause of pregnancy-related illness and death, there is now compelling evidence that preeclampsia and other complications of pregnancy increase an individual’s future risk of heart disease. A landmark study published in late January demonstrated in a population of more than 1 million Danish women that those who have experienced preeclampsia are at much higher risk of heart attack or stroke — even at young ages and fewer than 10 years after delivery. A second study published in February of more than 2 million women in Sweden showed similar findings at the population level.

These population-level findings appear to translate to observable changes in individuals’ cardiovascular systems. This week, another study out of Sweden shows that women who have experienced adverse pregnancy outcomes, particularly preeclampsia and gestational hypertension, have more extensive coronary artery disease than would be expected based on their traditional cardiovascular risk assessment. As noted in the accompanying editorial, there is now growing recognition that traditional cardiovascular risk calculators fall short for women, failing to account for the significant impact that pregnancy could have over a lifetime.

The strong connection between preeclampsia and future heart disease, along with the record number of cardiac deaths, should serve as a warning that sex-specific risk factors are a critical component to assessing risk and preventing future disease for women.

What’s causing record-high rates of preeclampsia and cardiovascular deaths?

Some have posited that the increase in pregnancy-related high blood pressure disorders and heart disease could simply be due to more older women having babies and an aging population, respectively. That could be part of the explanation. But when age is factored into the analysis, rates of high blood pressure in pregnancy and heart disease are both climbing. This means that a 25-year-old woman today is significantly more likely to develop high blood pressure in pregnancy compared to a 25-year-old in 1960. Likewise, a 75-year-old woman today has a higher likelihood of dying from heart disease than her forebears.

While all of the reasons for these trends aren’t fully understood, factors such as increasing obesity, sedentary lifestyle, external stressors, and even the environment may be contributing factors.

Getting ahead of these crises

Everyone — especially pregnant people and their clinicians — should start viewing pregnancy as a critical window to the future as well as an opportunity to reverse cardiovascular risk. Among the complications in pregnancy, preeclampsia is the strongest predictor of heart disease, associated with a fourfold increase in the risk of heart failure and a twofold increase in the risk of coronary heart disease, stroke, and death due to cardiovascular disease. But other pregnancy-related complications also affect that risk, including gestational diabetes, preterm birth, and other adverse outcomes, which are now included on the list of risk enhancers in prevention guidelines published by the American Heart Association and American College of Cardiology.

Far too few pregnant people and their clinicians are aware of this change.

By incorporating pregnancy into standard assessments for patients, clinicians can provide more personalized care and help prevent cardiovascular disease and its potentially devastating outcomes. Even simple interventions, such as more frequent blood pressure checks, can translate to large impacts on health and prevention.

Taking a detailed pregnancy history may also inform clinical decision-making on whether to start a patient on a statin or obtain more testing. Many people with a history of preeclampsia get “low risk” scores on traditional assessments, and would not be recommended for more in-depth testing, like checking for the amount of calcium lining the heart’s arteries, a sign of heart disease. But in the latest Swedish study, those with a history of preeclampsia had worrisome coronary calcium scores, meaning that outside of the research setting, many individuals at high for future cardiovascular disease are flying under the radar.

Change at the societal level to address these crises

While there are opportunities to improve care by recognizing the impact that pregnancy and its complications can have across the lifespan, women’s heart health — and pregnancy health — still need to be prioritized on a larger scale. Women’s health is notably underfunded compared to other areas, and the effect of this lack of investment shows.

There has been staggeringly more innovation in cardiology compared to obstetrics, reflecting the comparatively low resources invested in women’s health. A glance at the FDA’s listing of breakthrough device designations illustrates this divide. The FDA granted breakthrough status to 728 devices as of October 2022. The highest number of designations, 167, were for cardiovascular devices, a well-funded field. In obstetrics, which receives far lower funding, only four breakthrough device designations have ever been granted. Gynecology does not appear on the list, presumably because no breakthrough devices have ever been approved for it.

Women are also notably absent in clinical research: In every disease area, including cardiovascular health, women are underrepresented compared with their proportion of disease burden. This translates to less innovation for women and worse outcomes.

Heart disease, as the leading cause of death for both men and women, clearly deserves substantial research funding. But it’s also time to address the disproportionately low funding for women’s health, and the accompanying underwhelming investment, research, and progress for women’s health in general, including women’s cardiovascular health. Women, who are equally affected by heart disease as men, have unequal risks that urgently demand examination and attention.

Pregnancy is a window to the future and represents a unique opportunity to start reversing these unequal risks.

Nisha Parikh is a cardiologist in the multidisciplinary Pregnancy and Cardiac Treatment Program at the University of California, San Francisco, an associate professor of cardiovascular medicine at UCSF, and a volunteer with the American Heart Association. Alison Cowan is an OB/GYN hospitalist, a preeclampsia survivor, and head of medical affairs at Mirvie, a South San Francisco-based biotech company developing technology to predict and help prevent preeclampsia and other adverse pregnancy outcomes. The views expressed here are those of the authors and do not necessarily reflect those of their employers.