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 pump even more blood and support your developing baby. These changes aren’t as obvious as 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 notify your doctor if you have these symptoms, they are usually nothing to worry about.
Some heart-related changes or conditions can be serious, however. In fact, heart disease is now the leading cause of death in pregnancy and the postpartum period, according to a May 2019 guidance released by the American College of Obstetricians and Gynecologists (ACOG).
Understanding how pregnancy affects your heart can help you figure out what’s normal, what isn’t and what you can do to protect your health.
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.”
Other experts feel strongly about this too. “Pregnancy is a natural stress test…the cardiovascular system must undergo major changes to its structure to sustain tremendous increases in blood volume,” writes James Martin, MD, chair of the Pregnancy and Heart Disease Task Force, in a May 2019 ACOG statement.
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 may 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 second trimester, your blood pressure may also drop slightly due to hormonal shifts and the fact that more blood is flowing to your uterus. Your heart function won’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:
- Shortness of breath
- Feeling faint or light-headed
Additionally, you could develop an irregularity with your heartbeat or experience heart palpitations—the sensation that your heart skipped a beat. This fluttering feeling can occur as a result of many different changes during pregnancy, including hormonal changes.
Nearly 90 percent of pregnant women 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 ramps up.
These changes are usually not cause for concern but it’s always important to discuss any new or worsening symptoms with your doctor, especially if you notice them 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 peripartum cardiomyopathy, a weakening of the heart muscle that develops during pregnancy, accounting for 23 percent of late postpartum deaths.
To catch any heart-related condition during pregnancy, it’s important to see your doctor regularly, and discuss your medical history before becoming pregnant. In addition, ACOG is now recommending that all women are evaluated for cardiovascular disease both during pregnancy and after. If you are diagnosed with a heart condition, you and your doctor should be monitoring it closely before and during 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 possible 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 as well as 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 doctor 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 defects: These are problems with the heart that develop before birth, that are usually related to genetics or environmental factors. These defects, 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. Women with a congenital heart defect may have a greater risk of having a baby with a similar abnormality. Such defects can be spotted and monitored on ultrasounds 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 defect.
More severe heart problems could pose potentially life-threatening risks to pregnant women, such as:
- 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 your doctor so they can determine if it is safe for you to become pregnant. Then, they can advise you about all of your family planning options.
Ways to protect your heart
There are things you can do to reduce your risk for preventable heart-related problems and help control any existing health issues. Taking the following steps can help ensure that your ticker 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,” Pizarro says. All medications they are taking will also need to be reviewed to make sure they are safe during pregnancy, she adds.
No matter what your heart condition, talk with your doctor as soon as you decide you’re ready to start a family. Certain medication adjustments or other health provisions can be made ahead of time, to ensure your body is ready to carry a baby. And if you have heart disease, ACOG recommends you see a cardiologist before trying to conceive so you can receive pre-pregnancy counseling. If you do get pregnant and haven’t discussed your health conditions or treatment options, notify your OBGYN as soon as possible.
- Listen to your body: Increased hormone levels and a faster pumping heart can certainly make you feel more tired during pregnancy—especially in the first trimester as the placenta is forming and vital organs are developing. Take naps or lay down when you’re feeling drained or exhausted. Taking breaks may help reduce your risk for pregnancy-related complications, like preeclampsia.
“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. If possible, sleep on your left side. This will help take pressure off major blood vessels and will also 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 doctor about some safe 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 Institute of Medicine created specific guidelines when it comes to weight gain during pregnancy, so you should talk to your doctor about what is right for you. Most women should gain between 11 and 40 pounds, depending on their pre-pregnancy weight.
Staying within these parameters not only helps prevent gestational diabetes and helps with proper fetal growth, but also lowers your risk of conditions like hypertension and preeclampsia.
Try adopting a diet rich in nutrients and keep exercising regularly (as long as your doctor has cleared you to workout). Talk to your doctor if you have questions about weight gain—or loss. They should discuss specifics with you, like the types of exercises you should include in your routine, how often you should do them and at what intensity level.
- Keep all of your perinatal appointments: Of course, one of the most important aspects of a healthy pregnancy is consistently connecting with your OBGYN. “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.
Your heart plays a major role during pregnancy, and managing any heart issues prior to pregnancy, regularly checking-in with your doctor and practicing heart-healthy habits can help keep your ticker strong when you’re expecting.
Sourcing: American Heart Association, Merck Manuals, Cleveland Clinic, U.S.. National Library of Medicine, Northwestern Medicine, American College of Obstetricians and Gynecologists, CDC, American Pregnancy Association