In many ways, pregnancy can be seen as nature's stress test on the heart. Why? As soon as a woman becomes pregnant, a cascade of changes begins in the body, including a dramatic rise in blood flow and extra workload on the heart. These are all healthy and normal parts of helping to nourish the growing baby, and most moms-to-be won't have any heart troubles during pregnancy.
But for a growing number of women, pregnancy may bring about new, often temporary spikes in blood pressure (gestational hypertension or preeclampsia ) or blood sugar levels (gestational diabetes). These conditions typically go away soon after childbirth. But having them at all has been linked to a greater risk of developing heart disease later in life.
For example, having had preeclampsia doubles the risk of having a future heart attack or stroke and quadruples the risk of high blood pressure, according to experts. In addition, it seems preterm birth (having a baby before 37 weeks of pregnancy) regardless of the reason may also be a red flag for future heart issues and stroke.
If you've had high blood pressure—including gestational hypertension or preeclampsia—gestational diabetes, or delivered a baby earlier than 37 weeks, listen up. Although these conditions often disappear after having a baby, simply experiencing them puts you at much greater risk of heart disease or stroke in the next 10 years.
In this article, we will briefly review each of these conditions and what you can do, including questions to ask your health care team.
Why Does the Heart Work Harder During Pregnancy?
A host of changes occur when you are pregnant. For example:
Because of all these changes—and a growing baby—you may tire more easily or feel short of breath or lightheaded when doing things that require physical effort or when talking.
In addition, hormonal and metabolic changes affect how blood sugar levels are regulated. Changes in how your body forms clots needed to prevent excessive bleeding after delivery make pregnant women more prone to develop blood clots in the legs (called deep vein thrombosis).
For some women, pregnancy can lead to (mostly temporary) complications that may make heart disease or stroke more likely down the line. These conditions are sometimes called "adverse pregnancy outcomes."
Researchers don't yet know whether pregnancy causes these issues or if a woman's predisposition to heart problems first shows itself during pregnancy. But more awareness and action is needed to better meet the health needs of women with these conditions. Many experts suggest these women should be screened for cardiovascular disease over time and given tips on heart-healthy living.
"Because these conditions disappear after pregnancy, they can be quickly forgotten. Often no one talks about or follows up on a woman's increased and ongoing cardiovascular risk." — Martha Gulati, MD, FACC
What it is: Preeclampsia occurs when a pregnant woman develops high blood pressure and protein in the urine after the 20th week of pregnancy. A urine sample is taken at most obstetrician visits to check for this condition. It affects up to 8% of all pregnancies and usually occurs in mid-to-late pregnancy and up to six weeks after delivery.
Some women get high blood pressure for the first time during pregnancy without protein in the urine (also called gestational hypertension), which alone is concerning and can complicate pregnancy. It also can lead to preeclampsia.
In particular, preeclampsia may be characterized by:
Symptoms of severe preeclampsia may include headache, changes in vision, stomach pain, nausea or vomiting.
Why the concern: Preeclampsia can be very dangerous—and sometimes even life-threatening—for mom and her unborn baby. It can lead to seizures (eclampsia), damage to the liver and blood cells (HELLP syndrome), stroke and early birth. If you have preeclampsia, your health care team will monitor you closely and will induce labor at 37 weeks to prevent further problems.
But even after preeclampsia goes away—often within weeks to a few months after having a baby—women who've had it are more likely to develop heart and vascular problems, including:
And this risk remains over time. One study showed that compared with women with normal blood pressure readings during pregnancy, those who developed preeclampsia had a higher risk of high blood pressure over the next four decades.
What you can do:
Half of women who had preeclampsia did not receive any additional information or follow-up after three months of delivering a baby.
What it is: A form of diabetes in which the body doesn't produce enough insulin to control blood sugar during pregnancy. As a result, women have higher than normal blood sugar (glucose) levels.
Gestational diabetes, which affects 7%-9 % of pregnancies, usually starts around the 24th week of pregnancy, which is why a blood sugar test is often done between 24 and 28 weeks of pregnancy. If you develop diabetes during pregnancy, careful blood sugar monitoring, diet, exercise and taking insulin, if needed, are important.
Why the concern: In most cases, this type of diabetes goes away soon after childbirth. But having it heightens your risk for type 2 diabetes later. In fact, half of all women who had pregnancy-related diabetes will develop type 2 diabetes, according to the Centers for Disease Control and Prevention.
Diabetes at any age makes heart disease more likely. Experts say that even if you don't develop diabetes at some point after your delivery, a history of gestational diabetes still puts you at risk of heart disease. It can also damage some organs (for example, your heart, kidneys, nerves or eyes) by causing changes to the blood vessels that supply them. Yet most women are not followed for this condition after pregnancy.
What you can do:
Only 1 in 5 women who had gestational diabetes were tested again within six months of pregnancy to find out if they had diabetes, according to a study. Ask to have your blood sugar level re-checked.
What it is: When a baby is born too early, before 37 weeks of pregnancy (about three weeks before a baby's expected due date). Preterm births affect about 1 out of 10 pregnancies in the U.S.
Why the concern: Research has linked early deliveries to a higher risk of cardiovascular disease, cardiac events and related hospitalizations in moms. In fact, a recent review of existing studies found that preterm birth is associated with up to a 2-fold higher chance of developing or dying from heart disease or stroke later in life. The risk of heart and vascular diseases appears to be even greater among women who:
What you can do:
If you or a loved one had preeclampsia or diabetes during pregnancy or a preterm birth, don't despair. You can take steps to protect your heart and overall health post-pregnancy. Start with knowing your increased risk for cardiovascular issues and reminding your doctors about your health history.
Stay positive and live a heart-healthy lifestyle:
Know and keep up with your risk for heart disease and stroke; remember to talk with your health care team if you had problems during pregnancy—even if they have gone away. You can work together to come up with a plan to track and manage your risk over time.
It's important to talk with your OB/GYN and, even more important, your primary care doctor who will care for you for many years to come after you're done having children. Here are some questions to help start and continue the conversation:
In addition to resources on CardioSmart.org, you can learn more about acquired heart risks in pregnancy at the following websites:
American Diabetes Association
search 'gestational diabetes'
American Pregnancy Association
March of Dimes
Medline Plus - U.S. Library of Medicine
search 'preeclampsia', 'gestational diabetes' or 'preterm or premature birth'