Mariane Khoury
Project: Impact of pregnancy on a mother’s third trimester heart function and the heart and blood vessel relationship in the context of maternal heart disease
“High-quality research depends on careful collaboration, organization and communication across a large team. This experience showed me that research is not an individual process, but a collective effort in which every person and every step plays an important role in producing meaningful and reliable findings.”
Summary: Heart disease during pregnancy affects about four per cent of all pregnancies and is the leading cause of maternal death. This includes women born with heart conditions as well as those who develop heart disease later in life. The number of affected pregnancies is increasing because advances in medical care allow more children with heart disease to survive into adulthood, and many have children at older ages. Although most individuals with heart disease can become pregnant, the pregnancies carry higher risks for both mother and baby, including heart rhythm problems, heart failure, high blood pressure disorders of pregnancy, preterm birth and babies who are smaller than expected at birth.
In a healthy pregnancy, the mother’s heart must pump 30 to 45 per cent more blood to meet the needs of the growing baby and placenta. This is supported by changes in heart function and blood vessel relaxation, which lowers resistance to blood flow. In those with heart disease, these changes may not occur adequately. Some individuals cannot increase blood flow due to weakened heart muscle, valve disease or stiff blood vessels. Not all individuals with heart disease who experience complications have obvious heart failure, suggesting that blood vessel health may play an important role.
This study uses data collected over the past five years from a prospective research study of pregnant women, some with heart disease and some without (healthy controls). We will analyze heart ultrasound scans performed at 28-34 weeks of pregnancy, when the heart is under greatest strain. A key focus is ventricular-arterial coupling, which reflects how well the heart and blood vessels work together. Earlier results from the second trimester showed a mismatch between heart function and blood vessels in mothers with heart disease, especially in those with more severe disease. We hypothesize this mismatch will worsen later in pregnancy and may be linked to worse pregnancy outcomes for the mother and her baby.
Marianne Khoury was supervised by Dr. Lisa Hornberger in the Department of Pediatrics in the Faculty of Medicine & Dentistry. Her WCHRI summer studentship was jointly funded by the Stollery Children’s Hospital Foundation and the Alberta Women’s Health Foundation. She is in the doctor of medicine program at the University of Alberta.
Read more about WCHRI’s training awards for students at all levels and generous grants for researchers. See the rest of the 2026 summer studentship recipients here.
