Pregnancy is a natural stress test on the heart. Why? As soon as a woman becomes pregnant, many changes begin 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 or blood sugar levels.

• High blood pressure in pregnancy, also referred to as hypertensive disorders of pregnancy, may be pregnancy-induced high blood pressure (gestational hypertension), preeclampsia, or eclampsia. It also can be due to chronic high blood pressure.
• Elevated blood sugar during pregnancy, specifically if you had gestational diabetes, increases your risk for heart disease and diabetes as well.

These conditions typically return to pre-pregnancy levels soon after childbirth. But having them at all has been linked to a greater chance of developing heart disease, future high blood pressure and diabetes later in life.

In addition, it seems preterm birth (having a baby before 37 weeks of pregnancy) may be a red flag for future heart issues and stroke. Also, if you delivered a small baby, known as small for gestational age (in the lowest 10^th percentile), you are at a greater risk for heart disease as well. 

Take Charge of Your Health

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. Here are steps you can take:

• Make sure your health and heart are protected.
• Let your health care providers know if you developed any of these conditions during pregnancy, and encourage other women to do so, too.
• Learn about your risk of heart disease and stroke now and in the future.

Why does the heart work harder during pregnancy?

A host of changes occur when you are pregnant. For example:

• The amount or volume of blood in your body increases about 50%.
• Your heart begins to pump a lot more blood out to the body each minute (increased cardiac output).
• Your heart rate quickens – usually by 10-15 beats per minute.
• Your blood pressure drops a bit due to changes in hormones.

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).

Red flags for future heart problems

For some women, pregnancy can lead to (mostly temporary) problems that may make heart disease or stroke more likely in the future. 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.

High Blood Pressure and Preeclampsia

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:

• Blood pressure of 140 mmHg/90 mmHg or greater
• Protein in the urine
• Swollen feet, legs, fingers and hands

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:

• Risk factors such as high blood pressure and diabetes
• Heart disease
• Stroke

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

• If you had high blood pressure or preeclampsia during pregnancy, make sure this information is added to your health records for follow-up.
• Also, tell all your doctors that this problem occurred.
• Talk with your provider about your risk for heart disease.
• Advocate for yourself and commit to a heart-healthy lifestyle.
• Remember: You are more likely to develop preeclampsia again with future pregnancies, so talk with your doctor.

Gestational Diabetes

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.  Also, the baby may be large at birth, frequently over 9 pounds.

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 returns to pre-pregnancy blood sugar levels soon after childbirth. But having it at all heightens your risk for type 2, or adult onset, diabetes later in life. In fact, about half of all women who had pregnancy-related diabetes will develop type 2 diabetes, according to the Centers for Disease Centers for Disease Control and Prevention 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.

It’s important to follow up with your health visits and pay close attention to blood sugar, weight, diet, lifestyle and cardiovascular risk factors.

What you can do

• Make sure all your doctors know that you had diabetes during pregnancy and that it is noted in your health history.
• The American Diabetes Association recommends testing again for diabetes at 6-12 weeks postpartum; if your blood sugar level is normal, remind your doctor to check your blood sugar every one to three years to ensure it is detected early.
• Talk with your care team about ways to prevent or delay the onset of type 2 diabetes through exercise, eating a healthy diet and taking medications, if needed.
• Ask about other heart disease risk factors and how to prevent or manage them.

Preterm Birth

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:

• Deliver before 32 weeks of pregnancy
• Have had more than one preterm birth
• Have a preterm birth due to a medical cause (not an early delivery that happens on its own)

What you can do

• Tell your primary care doctor and other health care providers that you had a preterm birth. This information should be part of your ongoing health history long after the baby arrives.
• Ask about doing a formal heart disease risk assessment
• Work together to decide when and how often you need to be followed.
• Live heart healthy by exercising daily, eating right, not smoking, managing stress, and knowing your cholesterol and blood pressure numbers.

Tips for Taking Care of You

Don’t despair if you or a loved one had a hypertensive disorder of pregnancy, such as preeclampsia, or diabetes during pregnancy, or a preterm birth. You can take steps to protect your heart and overall health post-pregnancy.

Start with knowing your likelihood for developing cardiovascular issues and reminding your doctors about your health history.

Stay positive and live a heart-healthy lifestyle:

1. Adopt a healthy eating plan, such as a plant-based one
2. Get regular exercise
3. After your pregnancy, reach and maintain a healthy body weight
4. Avoid smoking
5. Limit how much alcohol you drink
6. Get enough sleep
7. Manage stress
8. 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 were years ago or have gone away. You can work together to come up with a plan to track and manage your risk over time.