A new study has revealed that women who give birth to four or more children are at higher risk of developing cardiovascular diseases than women who have fewer children. Researchers suggest that one possibility for this finding might be that women who have many pregnancies may have more visceral fat (fat around abdominal organs), and this has been linked to increased heart disease risk. Another possibility could be that increased cholesterol and higher blood sugar associated with pregnancy may lead to an increased risk.
Monika Sanghavi, Indian-American researcher from University of Texas's Southwestern Medical Center in Dallas, and lead author of the study, said, "This study adds to a body of evidence that pregnancy, which generally occurs early in a woman's life, can provide insight into a woman's future cardiovascular risk."
Researchers used data gathered for the Dallas Heart Study and compared the number of live births reported by women in the study with their coronary artery calcium (CAC) levels and aortic wall thickness (AWT). High levels of coronary artery calcification and thicker aortic walls are markers of heart disease that show up well before symptoms develop. Women were divided into three groups- one or no live births, two to three live births, and four or more live births.
Women who reported four or more live births had a 27% prevalence of a high calcium score compared with 11% among those with two to three live births. A similar trend was seen when looking at AWT measurements. Sanghavi said, "The associations were not affected by adjusting for socio-economic status or traditional cardiovascular risk factors, suggesting that physiological changes associated with pregnancy may account for the change."
Amit Khera, associate professor of internal medicine and senior author of the study, said, "We are learning that there are numerous physiological changes during pregnancy that have consequences for future heart health. This study reminds us of the importance of taking a pregnancy history as part of cardiovascular disease screening."