New research shows that postmenopausal women who reached menopause at an earlier age or who never gave birth at all are at a higher risk for developing heart failure.

The study, published in the Journal of the American College of Cardiology, builds on previous research that found hormones present during a women’s reproductive period can influence her risk of getting heart disease and that women who enter menopause early could be at an elevated risk.

In the current study, led by Nisha I. Parikh, MD, the lead author on the study and an assistant professor at the University of California, San Francisco School of Medicine, investigators examined more than 28,000 postmenopausal women without cardiovascular disease, who were compiled from the Women’s Health Initiative. The researchers looked at the association between the number of children participants had, their age during their first pregnancy, their total reproductive duration and whether they had incidents of heart failure.

After about 13 years, 5.2 percent of women were hospitalized for heart failure. Short total reproduction duration, or entering menopauses early, was associated with an increased risk of heart failure. Women who never had children were also found to be an increased risk for diastolic heart failure, while having more children was not associated with any increased heart failure risk.

"Our finding that a shorter total reproductive duration was associated with a modestly increased risk of heart failure might be due to the increased coronary heart disease risk that accompanies early menopause," Parikh said in a statement. "These findings warrant ongoing evaluation of the potential cardioprotective mechanisms of sex hormone exposure in women."

Though Parikh noted it’s not clear why there is an association between early menopause and heart disorders, the information could help better inform providers.

In an accompanying editorial, Nandita S. Scott, MD, co-director of the Corrigan Women’s Heart Health Program at Massachusetts General Hospital, said the study is a solid foundation for future studies on the topic.

"There also remain many unresolved questions including the mechanisms of estrogen's cardioprotective effect, making this truly a work in progress," Scott wrote. "Altogether, these findings raise interesting questions about the cardiometabolic effects of sex hormone exposure over a woman's lifetime and continue to raise important questions for future research."