Association between Number of Live Births and Markers of Subclinical Atherosclerosis: The Dallas Heart Study

Abstract

Aims

Higher parity has been associated with increased maternal risk of cardiovascular (CV) disease, but the mechanism is not well delineated. Whether the number of live births is associated with coronary and aortic subclinical atherosclerosis has not been fully evaluated.

Methods and Results

Women from the Dallas Heart Study, a multiethnic population-based cohort of subjects aged 30–65, were included if they had data on self-reported live births and coronary artery calcium (CAC) measured by computed tomography or aortic wall thickness (AWT) by MRI. CAC was positive if >10 Agatston Units, and AWT if greater than the 75 ^th percentile reference point for age and gender. Among the 1644 women included in the study, the mean age was 45 years and 55% were black. Sequential multivariable models were done adjusting for age, race, traditional CV risk factors, body mass index, income, education, hormone replacement therapy, oral contraceptives, and physical activity. Using women with 2–3 live births as the reference, those with 4 or more live births had an increased prevalence of elevated CAC (OR 2.2, 95% CI 1.28–3.65) and AWT (OR 1.6, 95% CI 1.04–2.41). Women with 0–1 live births also had increased CAC (OR 1.9, 95% CI 1.16–3.03) and AWT (OR 1.5, 95% CI 1.05–2.09) after multivariable adjustment.

Conclusion

The number of live births is associated with subclinical coronary and aortic atherosclerosis, with an apparent U-shaped relationship. Further studies are needed to confirm this association and explore the biological underpinnings of these findings.