Updated on April 21, 2023.
Each day your heart beats about 100,000 times and pumps roughly 2,000 gallons of blood throughout your body. During pregnancy, it works harder to circulate even more blood while supporting your developing baby. These changes aren’t visible like your growing belly, but you may notice that you’re more tired or short of breath. You could also feel a “fluttering” sensation in your chest. While you should always notify a healthcare provider (HCP) if you have these symptoms, in most cases they are nothing to worry about.
Some heart-related changes or conditions can be serious, however. In fact, heart disease is the leading cause of death for pregnant people and those in the postpartum period in the United States.
Understanding how pregnancy affects your heart can help you figure out what’s typical, what isn’t, and what you can do to protect your health during and after pregnancy.
How pregnancy affects the heart
When you’re expecting, your heart sends more blood to your uterus so that your fetus receives the oxygen and nutrients needed for proper growth and development.
“During pregnancy a woman’s blood volume increases up to about 50 percent so her heart has to work that much harder to pump,” explains Jade Pizarro, MD, an OBGYN at Orange Park Medical Center in Jacksonville, Florida. “The heart has to give blood to a growing uterus, placenta, and fetus, as well as enlarging breasts or other areas of the body that change during pregnancy.”
As the amount of blood in your body increases, you can anticipate these additional changes:
- Your cardiac output, or the amount of blood your heart pumps each minute, will jump 30 to 50 percent.
- Your resting heart rate will increase from about 70 beats per minute to up to 90 beats per minute.
- Your expanding uterus could slow the flow of blood from your legs and pelvic area back to your heart.
During your first and second trimesters, your blood pressure may also drop slightly. This usually returns to your typical level in the third trimester. Your overall heart function doesn’t return to pre-pregnancy levels until about six weeks after you deliver.
Symptoms to expect
While your heart is working overtime during pregnancy, you may notice some symptoms, including:
- Fatigue
- Shortness of breath
- Feeling faint or light-headed
Additionally, you could develop an irregularity with your heartbeat or experience heart palpitations. This feeling of fluttering or that your heart skipped a beat can be a result of several cardiovascular, hormonal, and emotional changes during pregnancy. In most cases, heart palpitations during pregnancy are not a cause for alarm.
Many pregnant people also develop a heart murmur, which is an unusual “swishing sound” between heartbeats. This can occur as the volume of blood flowing through the heart increases.
These changes are usually not cause for concern, but it’s always important to discuss any new or worsening symptoms with your HCP, especially if you notice them while at rest. In some cases, they could be a warning sign of a problem that requires treatment.
Possible heart-related complications
Some women have a heart-related condition that isn’t detected until they become pregnant and the extra strain on their heart worsens the problem. Others can develop an uncommon type of heart failure called peripartum cardiomyopathy, a weakening of the heart muscle that develops during pregnancy.
From 2016 to 2018, peripartum cardiomyopathy accounted for 12 percent of pregnancy-related deaths. Black, American Indian, and Alaskan Native women, as well as women over age 40, are more at risk for cardiomyopathy.
To catch any heart-related condition during pregnancy, it’s important to see your HCP regularly and discuss your medical history before becoming pregnant. The American College of Obstetricians and Gynecologists (ACOG) recommends that all women are evaluated for cardiovascular disease during pregnancy and after. If it turns out that you are diagnosed with a heart condition, you and your HCP should monitor it closely before, during, and after pregnancy.
Many women with heart conditions go on to have healthy babies, but pregnancy can exacerbate some of these issues and lead to complications. Some heart-related conditions that may be affected by pregnancy include:
High blood pressure: Women who develop high blood pressure before or during pregnancy have an increased risk for a complication called preeclampsia. This is a serious condition characterized by high blood pressure, sudden weight gain, and protein in the urine. Preeclampsia can lead to kidney and liver damage, and later in life increases the risk of heart disease. It also increases the risk for placental abruption (or the separation of the placenta from the uterine wall), preterm birth, low birth weight, or Cesarean delivery.
If you have high blood pressure, your HCP will track your numbers and may ask you to use an at-home heart monitor. Your symptoms will also be monitored for signs of preeclampsia, including headache, nausea, shortness of breath, dizziness, or blurred vision.
Congenital heart issues: These are problems with the heart that develop before birth and that are usually related to genetics or environmental factors. These variances, which may involve the heart’s walls or valves as well as the arteries and veins near the heart, can disrupt the normal flow of blood.
Pregnant people with a congenital heart issue may have a greater risk of having a baby with a similar condition. These can be spotted and monitored on ultrasound scans throughout pregnancy, and certain conditions can be treated during pregnancy.
Prior to pregnancy, a cardiologist can also anticipate any problems you may have during pregnancy and offer genetic counseling to help determine how likely it is that your child will have the condition.
Other heart issues: More severe heart problems that could pose potentially life-threatening risks to pregnant women include:
- Pulmonary hypertension: high blood pressure in the blood vessels of the lungs
- Cardiomyopathy: a disease that causes the heart muscle to become damaged and weakened, which affects the heart’s ability to pump blood
- Marfan syndrome: a disease that affects the connective tissue, which can weaken the aorta, the large artery that supplies blood throughout the body
- Heart failure: a chronic condition that occurs when the heart isn’t pumping as well as it should
If you’re affected by one of these serious conditions, you should be evaluated by an HCP to determine if it is safe for you to become pregnant. Depending on the outlook, they can advise you about your family planning options.
Pregnancy as a “stress test”
Receiving certain heart-related diagnoses during pregnancy can help predict future cardiovascular disease. In this way, pregnancy is often described as a natural “stress test” for those who have heart-related risk factors. In other words, the development of common pregnancy complications can serve as a preview and a warning for future heart disease.
Such conditions include:
- Preeclampsia
- Gestational hypertension (or high blood pressure)
- Gestational diabetes
- Placental abruption
- Pre-term birth
Pregnant people who develop these conditions may have an underlying and undiagnosed risk for heart disease.
By staying in close contact with your HCP during and after pregnancy—and being alert for any heart-related complications all the while—you may be able to lay the foundation for a healthier pregnancy and a healthier heart after delivery.
Ways to protect your heart
There are things you can do to reduce your risk for preventable heart-related problems and help manage any existing health issues. Taking the following five steps can help ensure that your heart stays strong for nine months and beyond:
Plan ahead. Any heart condition that you have should be under control before getting pregnant. “Women who have known heart conditions should consult with their doctors prior to planning pregnancy to make sure their body is able to undergo the changes involved with pregnancy,” Dr. Pizarro says. All medications you take will also need to be reviewed to make sure they are safe during pregnancy, she adds.
If you do get pregnant and haven’t discussed your health conditions or treatment options, notify a HCP as soon as possible.
Listen to your body. Increased hormone levels and a faster pumping heart can make you feel tired during pregnancy, especially in the first trimester as the placenta is forming and vital organs are developing. Take naps or rest breaks when you’re feeling drained or exhausted. “Rest helps to maintain normal bodily functions in addition to the extra work pregnancy puts on the body,” says Pizarro.
Prioritize sleep. It’s a good idea to improve your sleep quality by sticking to a consistent sleep schedule. Avoid sleeping on your back and, if possible, sleep on your left side. This will help take pressure off major blood vessels and improve placental blood flow.
Anxiety, excitement, back pain, frequent trips to the bathroom, and heartburn can all make it difficult to get enough sleep while pregnant. If you’re having trouble sleeping at night, talk with your HCP about lifestyle adjustments that could help, such as sleeping with a body pillow or limiting beverages before bedtime.
Maintain a healthy weight. Nausea and fatigue can make it harder to stick to a healthy diet during pregnancy (especially in the first trimester). But it’s important that you maintain a healthy weight throughout pregnancy. The Centers for Disease Control and Prevention (CDC) offer helpful guidelines when it comes to weight gain during pregnancy. Most women should gain between 11 and 40 pounds, depending on their pre-pregnancy weight.
Managing weight gain during pregnancy helps prevent gestational diabetes and helps with proper fetal growth. Your HCP can guide you the right combination of eating healthfully and getting regular exercise to achieve the pregnancy weight that makes the most sense for you.
Keep all of your perinatal appointments. One of the most important aspects of a healthy pregnancy is consistently connecting with your HCP. “Make sure you’re open and honest with your provider,” says Pizarro. “Keep them updated about changes you notice with your body or any concerns you have.” Doing so will allow them to address any concerns right away, so that you stay healthy during pregnancy and beyond.
