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Pregnancy is like a ‘stress test’ for the heart’

June 29, 2023 | Paul Taylor
Pregnant woman holding her belly

A woman's heart has to work harder and pumps as much as 50% more blood during pregnancy.

The tragic death of pregnant Olympic sprinter Tori Bowie last month due to “possible complications of childbirth” underscores the need to protect heart health during — and after — pregnancy.

Throughout pregnancy, a woman’s blood volume increases by as much as 50% as the heart works harder and pumps more blood through the body to support the developing fetus.

UCI Health high-risk pregnancy specialist Dr. Afshan Hameed, a leader in the field maternity and heart disease, compares pregnancy to “running on a treadmill for nine months.”

“It’s like a cardiac stress test,” she told the Washington Post.

The stress on the heart muscle and blood vessels can exacerbate undetected cardiovascular problems and may lead to dangerously high blood pressure, gestational diabetes and premature labor.

Cardiovascular disease (CVD) is responsible for more than one-third of all U.S. pregnancy-related deaths. But CVD is often undetected, misdiagnosed or dismissed in pregnant patients, resulting in delays in treatment for conditions that could lead to serious health problems and even death, according to Hameed.

The problem is of particular concern for Black patients like 32-year-old Bowie, who are three times more likely to die during or after pregnancy than their white counterparts. Studies show they also have higher rates of pre-existing heart disease, hypertension during pregnancy and peripartum cardiomyopathy than other racial and ethnic groups.

The three-time Olympic medalist was eight months pregnant and had been in labor when her body was found at her Florida home on May 2, 2023. An autopsy report cited the cause of death as complications of childbirth, possibly from respiratory distress and eclampsia, a pregnancy-related high blood pressure disorder that can result in seizures and coma.

Hameed believes that screening women early in their pregnancies for CVD could dramatically reduce maternal mortality. She is leading a national study testing pregnant and postpartum patients using an 18-point risk-assessment algorithm she helped develop to identify those who need close monitoring and further testing for heart problems.

A professor of cardiology, obstetrics and gynecology at the UCI School of Medicine, Hameed has been a longstanding leader in the field of maternity health and heart disease in pregnancy. Her clinical focus is on maternal cardiovascular disease, anticoagulation in pregnancy, valvular disease and the prevention of maternal morbidity and mortality. She helped develop cardiovascular and venous thromboembolism toolkits for the California Maternal Quality Care Collaborative. She also served on the American College of Obstetrics and Gynecology's Presidential Task Force on heart disease in pregnancy.

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