When you see a physician for the first time, the physician will ask about your family’s history of heart disease. The physician will also gather data about conditions like diabetes, obesity, high cholesterol, or high blood pressure.
You’re probably well aware that all of these are risk factors for heart disease.
What you may not know, is that when physicians ask women about their pregnancy history, they are also gathering information that can influence risk for heart disease.
Some of my colleagues at UT Southwestern Medical Center and I recently completed a study looking at information on women in a large database called the Dallas Heart Study. In this group, we compared the number of times a woman has given birth with two markers for “sub-clinical” (pre-symptomatic) heart disease.
We used imaging to measure calcium levels in the plaques that build up in the arteries of the heart. We also measured the thickness of the aorta, which is the main artery pipeline from the heart to the rest of the body. High levels of calcium in the coronary arteries and a thick aortic wall are indicators of heart disease.
Among the women in the Dallas Heart Study, patients who had given birth four or more times were more than twice as likely to have sub-clinical heart disease as patients who had given birth two or three times.
We know that women who develop pregnancy complications – such as gestational hypertension, preeclampsia, and gestational diabetes – have an increased risk of cardiovascular disease. This study suggests that there may also be a connection between the number of children a woman has and her future cardiovascular risk.
Here’s a possible explanation: When a woman is pregnant, temporary changes occur that can stress the cardiovascular system. She adds weight around her abdomen. Often her blood sugar levels will increase, her body becomes resistant to insulin, and her blood lipid levels will increase.
You probably recognize these as being conditions that increase heart-disease risk. It is possible that the more often a woman is pregnant, the more likely it is that her cardiovascular system will be affected by these temporary changes.
As physicians, this study is a reminder that pregnancy can provide information about a woman’s future risk of heart disease and it is important to get pregnancy history from our patients.