Women who have four or more live births may be at higher risk for cardiovascular disease compared with women who give birth to two or three children, research to be presented at American College of Cardiology (ACC) scientific session in Washington, D.C., found. The study also found women who have no children or one child may also be at higher risk for cardiovascular disease than women who have two or three children.

Researchers led by Monika Sanghavi, MD, of the University of Texas Southwestern Medical Center in Dallas, used self-reported data from women who participated in the Dallas Heart Study on the number of live births as well as data on coronary artery calcium (CAC) measured by CT or aortic wall thickness (AWT) measured by magnetic resonance imaging.

Among the 1,331 women in the study, the researchers found the number of live births associated with prevalence of CAC and AWT in a U-shaped pattern. Compared with women who had two or three live births, women who had four or more had a higher prevalence of CAC and AWT (odds ratio [OR] 2.9 and 1.7). Women with 0 or 1 live births also had a higher prevalence of increased CAC (OR 1.5) and tended to have higher AWT (OR 1.2), but neither value was significant.

“Recently, there is evidence that pregnancy might also function as a crystal ball, providing insight into a woman’s future cardiovascular risk and that the changes associated with pregnancy may have a longer-term impact on a woman’s health,” Sanghavi said during a press conference announcing the results of the study.

However, she added that the mechanism behind the association was not yet understood, but she and her colleagues hypothesized that it could be subclinical atherosclerosis or evidence of early coronary plaque buildup.

The research was among results the ACC made available before the studies’ scheduled presentation. ACC.14 will continue through March 31.