Cardiovascular risks could start before birth for some babies
Dr. Lisa Hornberger, a researcher at the University of Alberta and a member of the Women and Children's Health Institute, is studying the link between gestational diabetes in pregnancy and the long-term likelihood of heart disease, a complication that affects as many as one in seven pregnancies.
Cardiovascular disease, including hypertension, coronary artery disease and stroke, is responsible for one-third of all deaths worldwide. Many risk factors are related to poor lifestyle choices in adulthood. But Lisa Hornberger, a pediatric and fetal cardiologist, is examining the risks that may begin in the womb when a mother has gestational diabetes.
This condition, which occurs in women who did not have diabetes before pregnancy, typically begins in the middle trimester and can lead to problems for the mother, including high blood pressure.
Hornberger’s research project focuses on the long-term impact of gestational diabetes on babies, before and after birth. She and her team are doing cardiovascular assessments, using echocardiograms, to measure the health of the heart and blood vessels of children whose moms had gestational diabetes. They are also doing metabolic and blood studies on children, who are aged nine to 11.
The cardiovascular assessments are looking for evidence of arterial stiffness and thickening of the heart muscle, which are both signs that could indicate higher risks of long-term cardiovascular disease. The researchers are also looking at other risk factors—the children’s diet and physical activity levels since birth, the mother’s diet and activity during pregnancy, and how well her glycemic, or blood sugar, levels were controlled during pregnancy, especially in the third trimester.
“The question is, do the children have evidence of cardiovascular changes that would be indicative of potential risks long term?” explained Hornberger. “And are these changes things that are related to fetal exposure, post-fetal factors or a good combination of both? Is there a weighting on one versus the other?”
To gather information on mothers and babies going back years, Hornberger says her team has been fortunate to collaborate with the Alberta Pregnancy Outcomes and Nutrition, or APrON, project. It’s a study, mainly focused on nutrition, that has followed more than 2,000 Calgary and Edmonton mothers and their children for 10 years. “They have all of this beautifully collected data from the fetal stages,” says Hornberger. “It’s really been a godsend for the success of this study.”
Shelley Lamer and her daughter are part of the study. The Calgary mother had gestational diabetes for all three of her pregnancies but she had no idea that her children might carry a risk of long-term cardiovascular disease until she was approached to be part of Hornberger’s study.
While her daughter is very active and not overweight, Lamer says she is eager to learn the results of the study because heart disease already runs in her family. “It’s important work,” Lamer says. “I’m grateful that they’re doing it for people like me but I also think it’s important for the future.”
Recommendations that could arise out of the study will depend on the results. “There are some very nice data that has come out of this work,” says Hornberger, adding that publication plans are underway. If the findings show that third-trimester glycemic control is the highest risk factor, clinicians could place more emphasis on encouraging pregnant mothers to control their sugars through diet and medication or to lower their risk factors for developing gestational diabetes in the first place.
Hornberger says it will also be important to get the message out to mothers who had gestational diabetes, encouraging them to lower their children’s long-term cardiovascular risk after birth through a healthy diet and physical activity.
Sixty mothers from the APrON cohort—30 who had gestational diabetes and 30 who did not—and their children were recruited for Hornberger’s study. The cardiovascular and metabolic assessments began early in 2022 after a COVID-related delay and were finally completed in the spring.