Heart Problems Can Be a Major Risk During Pregnancy. They're Often Overlooked

For your heart, pregnancy is “similar to running on a treadmill for nine months,” says Afshan Hameed, MD, a professor of maternal-fetal medicine and cardiology at the University of California, Irvine. “It’s like a cardiac stress test.” 

Throughout your pregnancy, your body increases blood volume by 30 to 50 percent. Your heart beats faster to move more blood throughout the body. “These changes support a growing fetus, but it puts an extra workload on the mom’s heart,” says Kathleen Young, MD, cardiologist and co-director of the Mayo Clinic Cardiovascular Obstetrics Clinic in Rochester, Minn.

And if pregnancy is a marathon, labor and delivery is the final sprint. Blood pressure and heart rate can increase further during labor and delivery. And the effects of pregnancy on heart health don’t disappear right after the baby’s born. "The heart is still under extra stress as hormones fluctuate and the extra blood from your uterus returns to circulation," says Young.

With all the pressure on the heart, pregnancy may reveal undiagnosed cardiovascular issues, such as problems with blood vessel function or congenital heart defects (structural issues of the heart present at birth), says Gina Wei, MD, the National Heart, Lung, and Blood Institute’s senior scientific advisor on women’s health. In people who already have high blood pressure or diabetes, it may also worsen those conditions and increase their likelihood of having a cardiac event.

Even if you don’t have a heart problem, nearly 20 percent of pregnant people develop complications that can damage the heart or blood vessels, such as preeclampsia, gestational diabetes, and premature birth.

These conditions may resolve after pregnancy, but they may also cause blood vessel changes that nearly double the risk of developing heart disease later in life, says Wei. But only 1 in 5 women are aware that pregnancy can threaten heart health, according to a survey in the Journal of the American College of Cardiology.

And the risk isn’t only in the future. Up to 4 percent of all pregnant people have or develop heart disease during pregnancy—and research shows that that number is on the rise. Cardiovascular disease—diseases that affect the heart or blood vessels—is the leading cause of death during pregnancy and in the year after giving birth, accounting for 27 percent of pregnancy-related deaths, according to the American College of Obstetricians and Gynecologists.

Risk factors for developing heart problems during pregnancy include high blood pressure, obesity, and age. One research review published in 2019 in the journal Medicina shows that women who are age 35 or older are more likely to have heart-related issues during pregnancy compared with their younger counterparts. More women are delaying childbirth until their 30s and 40s, which, in part, explains the rising prevalence of pregnancy-related heart disease, says Elizabeth Langen, MD, a clinical associate professor of obstetrics and gynecology and obstetrics director of the cardio-obstetrics program at the University of Michigan.

Racial inequities play a role as well. For example, non-Latina Black women have 3 to 4 times the odds of dying of heart disease during pregnancy compared with white women. “Clearly systemic racism has an impact on health,” says Langen. It’s particularly important that doctors are attentive to any potential warning signs in people of color, she says.

But most of these deaths are avoidable with the right preventive measures, early detection, and the right treatment. The problem is that heart issues are easily overlooked, misdiagnosed, or mistreated, Langen says. Fatigue, swelling, and chest pain can be normal pregnancy symptoms, but they may also signal a heart problem. “Most healthy young people can tolerate a lot of stress on the cardiovascular system” before issues or complications occur, she says. “So they don’t look sick until they’re very sick."

One of the first steps to take—as soon as you’re thinking about getting pregnant—is creating a plan with your doctor to reduce heart disease risk factors, such as quitting smoking and reaching a healthy weight, says Wei.

This move can protect your heart during pregnancy—and for years down the road. One study in 2021 in the Journal of the American Heart Association found that first-time moms with heart disease risk factors before pregnancy or during their first trimester had greater odds of having a complication, such as preeclampsia or gestational diabetes. They were 7 to 15 percent more likely to develop high blood pressure two to seven years after giving birth.

While addressing heart health before pregnancy is best, even if you are already pregnant there’s still a lot you can do to reduce your risk.

Get screened early on. One analysis from the CDC Foundation, an independent nonprofit that supports the Centers for Disease Control and Prevention, revealed that 68 percent of pregnancy-related deaths caused by heart issues are preventable. Some of the main causes of these deaths included delayed diagnoses and missed screenings. If your OB-GYN doesn’t bring it up, ask them to do a heart health screening.

If you have an existing heart issue, talk to your doctor. People who already have heart problems may need to work with a cardiologist throughout their pregnancy. You may need a change in your current treatment, such as switching to a medication that’s safer during pregnancy, or taking baby aspirin to reduce your odds of preeclampsia.

Keep moving. Staying active helps to keep your weight, blood sugar, and blood pressure in check, says Young. One review published in 2017 by Italian scientists showed that doing about 30 to 60 minutes of aerobic exercise two to seven days a week reduced the risk of high blood pressure during pregnancy by 46 percent.

Speak up about your symptoms. Signs of heart trouble include shortness of breath, chest pain, racing heart, and swelling of the feet, ankles, and lower legs. “The problem is that many of these symptoms overlap with typical pregnancy symptoms,” says Young. “But if anything feels new, unusual, or out of proportion, don’t brush them off. Talk to your doctor.”

Scale back on highly processed foods. Fast foods, sodas, chips, and other ultra-processed foods are often high in calories and sodium, which contributes to high blood pressure. Brazilian scientists showed that women who ate a diet high in these foods during pregnancy were 48 percent more likely to develop gestational diabetes and had 28 percent higher odds of having preeclampsia.

Focus on fruits, vegetables, and whole grains. These foods serve up fiber, which can help keep your blood sugar and hunger in check. They’re also sources of vitamins and minerals that support heart health, such as potassium. Research shows that getting a potassium-rich diet may help lower blood pressure, especially in women who get too much sodium.

Prioritize your postpartum appointments. When you’re busy caring for a newborn, your own doctor’s appointments may get pushed to the wayside. As many as 40 percent of women skip their postpartum checkups, according to the American College of Obstetrics and Gynecology. But two-thirds of heart-related deaths due to pregnancy occur during the year after the baby’s birth. Make sure that you follow through on your follow-up appointments.

Share your pregnancy history. At future appointments, tell your doctor about any complications that you had during pregnancy. Many healthcare providers overlook this important topic. According to a survey of primary care physicians published in the Journal of the American College of Cardiology, only 16 percent ticked all the recommended boxes, such as asking about pregnancy complications, when assessing heart disease risk in women.

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