A woman who is pregnant has her blood pressure taken at a doctor's office.

Pregnancy is like the ultimate stress test: what new prospective parents need to know about heart health

New research shows that by tending to their cardiovascular health now, patients can get big benefits during pregnancy and beyond

It’s important to keep hearts healthy at every life stage, but how people take care of themselves leading up to and during pregnancy can affect their cardiovascular health for decades. Victoria Pemberton, a nurse and researcher in the Division of Cardiovascular Sciences at NHLBI, shares updates about what parents-to-be and new parents can do to protect their hearts during this critical period of their lives.

Why is pregnancy viewed as a window into future cardiovascular health?

Fortunately, most people have healthy pregnancies. However, for every 10 people who give birth, about one to two experience a complication.

About half of pregnancy complications are related to high blood pressure. These complications include preeclampsia, which is a sudden spike in blood pressure; eclampsia, a preeclampsia complication that can lead to seizures; and also a condition called HELLP, which can affect the blood and liver.

When a patient experiences a severe pregnancy complication, such as preeclampsia, gestational diabetes, or a preterm birth, their risk for developing heart disease later in life can nearly double. This is one reason why pregnancy complications are considered independent risk factors for heart disease.

What can people do to reduce the risk of having a pregnancy complication?

About half of pregnancy complications can be prevented. One of the first things a patient can do is talk to their doctor about risk factors before and leading up to their pregnancy. This can include creating a plan to reach and maintain a healthy body weight, get blood pressure and blood sugar under control, and support physical activity or regular movement. It can also include ways to create meals around heart-healthful foods while quitting or avoiding tobacco.

Making this kind of plan could be lifesaving for a lot of patients, especially for those with heart disease risk factors such as elevated blood pressure, blood sugar, or blood cholesterol. One study of almost 4,500 first-time parents found that those who had these risk factors before pregnancy or during their first trimester were more likely to experience a complication. These patients also had increased associated risks for developing high blood pressure two to seven years after giving birth.

This study was part of the nuMoM2b Heart Health study, and like other similar studies, it has helped underscore the power of prevention. What we know about high blood pressure is that the earlier you have it, the worse your outcomes for heart disease can be. If doctors and clinicians can partner with patients early to change that course, they have a much greater chance for helping patients reduce their risk for heart disease.

What should a patient tell their primary care doctor if they had a pregnancy complication?

One of the best things patients can do is share the details about that complication with their primary care doctor. When did it occur? How was it treated? What were the outcomes? A recent review in JAMA also recommended routine cardiovascular screenings for patients three months after pregnancy complications and then annually.

By working together with their doctor in these ways, a new parent has a better chance of reducing their risk for other conditions that have been linked to pregnancy complications: type 2 diabetes, stroke, early cognitive decline, and premature death.

Research has shown that pregnant people who are American Indian, Asian, Black, Hispanic, and Pacific Islander are more likely to experience adverse pregnancy outcomes, which exacerbates health disparities. What research might change these outcomes?

Pregnancy-related health disparities are staggering.

For example, Black patients are four times more likely to experience a severe event following preeclampsia compared to white patients. In 2020, researchers from across the NIH and other federal health institutes held a two-day workshop to discuss maternal health morbidity and mortality in the U.S.

This year, with the support of the White House, researchers are studying a range of solutions to support patients before, during, and after pregnancy.

What are a few examples?

Right now, NHLBI is supporting two community-focused maternal health research initiatives.

One study, the Maternal Health and Community Implementation Project (CIP), will assess how different approaches – such as pre-pregnancy screenings and guided support – may improve the cardiovascular health outcomes of patients before and during pregnancy.

Another, the Early Intervention to Promote Cardiovascular Health of Mothers and Children (ENRICH), is also supported by the Health Resources and Services Administration, and will evaluate how community-supported partnerships may help patients after pregnancy. In this study, researchers will evaluate if bringing medical care to communities – through at-home medical visits – can improve the cardiovascular health of 3,000 new parents and their children.

The NIH, along with the Bill & Melinda Gates Foundation, is also awarding a $1 million cash prize to a researcher or team that develops a diagnostic tool that can be used to improve pregnancy-related health outcomes and alleviate global health disparities.

How else are researchers studying cardiovascular disease risk factors in pregnancy?

Researchers continue to study ways to identify cardiovascular health risk factors – but at earlier stages. This includes pregnancy.

For example, in the journal Hypertension, researchers describe pregnancy-related health outcomes among thousands of patients who gave birth over a 10-year period. None of the patients in the study started their pregnancy with high blood pressure or had a previous pregnancy with preeclampsia. They shared about four blood pressure readings throughout their first 20 weeks of pregnancy, which helped the researchers study their early pregnancy blood pressure patterns.

What did they find?

The researchers used these blood pressure readings to design algorithms to predict patients at greater risk for experiencing adverse pregnancy outcomes, like preeclampsia or gestational diabetes. The researchers will expand on this study, but they noted the findings hint at ways early pregnancy blood pressure patterns may be used to personalize the monitoring and prevention of heart disease.

Pre-pregnancy obesity was another indicator that helped researchers identify patients at greater risk for experiencing blood pressure-related pregnancy complications.

Where can people go to learn more about pregnancy and heart health?

To learn about cardiovascular health and pregnancy, visit https://www.nhlbi.nih.gov/health-topics/education-and-awareness/heart-truth/listen-to-your-heart/heart-health-and-pregnancy.

To learn about ways to keep your heart healthy at every age, visit http://www.nhlbi.nih.gov/HeartMonth.