Pregnancy health centre

High blood pressure in pregnancy linked to later heart risks

By Sophie Ramsey

BMJ Group News

What do we know already?

High blood pressure during pregnancy is fairly common, with up to 10 in 100 pregnant women diagnosed with the condition (called gestational high blood pressure). Doctors monitor it closely, as it can lead to problems for both the woman and her baby, including a potentially life-threatening condition called pre- eclampsia.

Pre-eclampsia goes away once a woman has her baby. But it does mean that the woman has a raised risk of heart and circulation problems later in life. What’s less clear is whether other types of high blood pressure during pregnancy also carry this risk.

To learn more, researchers looked at more than 10,300 women who gave birth in Finland in 1966. Doctors had recorded their blood pressure readings while they were pregnant. The researchers then used health registries to track the women’s health for around 40 years, looking at whether those with high blood pressure during pregnancy were more likely to develop heart and circulation problems, kidney disease, and diabetes.

What does the new study say?

Around 36 in every 100 women had some form of high blood pressure during pregnancy, ranging from only one or two raised readings to pre-eclampsia.

Later in life, these women were more likely to develop high blood pressure and heart and circulation problems, compared with women who had normal blood pressure in pregnancy. They also had a higher risk of diabetes and kidney disease, which are both related to high blood pressure.

For example, women who had any high blood pressure during pregnancy were at least 14 percent more likely to develop cardiovascular disease later in life, compared to women with normal blood pressure during pregnancy. The risk was highest for women with pre-eclampsia, who were twice as likely as women without high blood pressure to develop cardiovascular disease.

The researchers also looked separately at measurements of the two different types of blood pressure: systolic and diastolic blood pressure. (In the blood pressure reading ‘140 over 90’, systolic pressure is the first number and diastolic pressure is the second.) The researchers found that women still had a raised risk of heart and circulation problems even if only one of these blood pressure readings was high during pregnancy.

How reliable is the research?

This was a very large study that gathered information from reliable sources. The researchers also took into account several things that can affect women’s risk of developing heart and circulation problems, including whether they were overweight or smoked. However, they only looked at whether women had these risk factors at the time they were pregnant. So the researchers couldn’t factor in whether these and other risk factors were present later in the women’s lives. This may have affected their findings.

What does this mean for me?

If you’ve had high blood pressure during pregnancy, these findings may sound alarming. But bear in mind that many things determine your chance of developing these conditions. There are steps you can take to lower your risk, such as exercising regularly, eating a healthy diet and not smoking. If you are concerned, you might speak to your doctor about your overall chance of these conditions, and ways you might lower your risk.