Pregnant women who experience certain complications related to their pregnancies may have an increased risk of dying from heart disease later in life, a new study suggests.
Researchers found that the women in the study who had high levels of sugar in the urine during pregnancy were about four times more likely to die from heart disease over the 50-year study, compared with the women who did not have high levels of sugar in their urine when they were pregnant.
The investigators also found that the women who experienced a decline in their levels of hemoglobin during pregnancy were about twice as likely to die from heart disease later in life, compared with the pregnant women who did not experience the decline. The level of hemoglobin in the blood is a measure of how well red blood cells can carry oxygen throughout the body, the researchers said.
"The idea here is not necessarily that these events of pregnancy cause women to die of cardiovascular disease," said study author Barbara A. Cohn, director of Child Health and Development Studies at the Public Health Institute in Berkeley, California. "The idea is that, just like a person's cholesterol level and blood pressure are considered risk factors [for heart disease], so should those pregnancy complications."
In the study, the researchers looked at about 15,500 women in the metropolitan area of Oakland, California, who became pregnant between 1959 and 1967. As of 2011, 368 women had died of heart disease. The average age of the women at the start of the study was 26, and 66 in 2011.
The researchers also found that having certain combinations of pregnancy complications was related to a significantly higher risk of death from heart disease. For example, the women who had both pre-existing high blood pressure (diagnosed before they delivered) and delivered their babies too early were about seven times more likely to die of heart disease later on than those who did not have this combination of complications. [Blossoming Body: 8 Odd Changes That Happen During Pregnancy]
The women who had pre-existing high blood pressure along with pre-eclampsia (a condition that involves high blood pressure and high levels of protein in the urine), were nearly six times more likely to die from heart disease than those who did not have this combination of complications, the scientists found.
The women who had pre-existing high blood pressure and whose babies were smaller than normal when they were born were almost five times more likely to die from heart disease, compared with the women who did not have this combination of complications, the researchers found.
Women who experienced any of these complications during pregnancy should mention them to their physicians later on, Cohn said. Also, physicians should ask women whether they had them, she said.
This way, their doctors can monitor these women's health more closely or make specific recommendations that may help lower their risk of dying from heart disease. "These findings are important because we think that by asking women about pregnancy history, doctors might be able to save lives," Cohn told Live Science.
The new study was published today (Sept. 21) in the journal Circulation.
Sign up for the Live Science daily newsletter now
Get the world’s most fascinating discoveries delivered straight to your inbox.