How Pregnancy Affects the Heart: Normal Symptoms & When to Call Your Doctor

Pregnancy puts additional stress on the heart and circulatory system because the body works harder than usual to grow the fetus. While you are pregnant, your blood volume goes up 40-50%. Your heart rate increases 10-20 beats per minute to pump more blood. Sometimes that extra stress leads to developing a heart condition during pregnancy.

It is important to get an early diagnosis and treatment for any new heart condition. Cardiovascular disease (CVD) is a leading cause of maternal death. But with proper care, most people who develop a heart condition during pregnancy will recover and can safely deliver a healthy baby.

Normally, blood pressure gradually decreases until the middle of the pregnancy. Then it steadily increases until reaching its original level by the end of the pregnancy. At your regular prenatal checkups, your doctor will check your blood pressure and heart rate at every appointment. A normal blood pressure reading is 120/80 mmHg and below, even during pregnancy.

If your readings are too high or too low, your doctor may recommend more tests to rule out or diagnose pregnancy-related heart problems, such as:

• Preeclampsia: Very high blood pressure and protein in the urine, which means the kidneys are in danger. It generally occurs after 20 weeks of pregnancy and is most common at full term (37 weeks). Blood pressure medication and bedrest may help, but the only “cure” for preeclampsia is delivering the baby. Your doctor may recommend inducing labor early to decrease the risk of complications.
• Gestational hypertension: Very high blood pressure in pregnancy with no protein in the urine. It typically develops after 20 weeks of pregnancy. Treatment may include medication and bedrest. It usually goes away after delivery.
• Blood clots: Deep vein thrombosis (DVT) is a condition in which blood clots form in the veins. During pregnancy, the blood clots more easily to prepare for blood loss during delivery. Increased estrogen levels can also increase the risk of blood clots, particularly in the legs or pelvic area. These natural changes in the body make pregnant patients 5 times more likely to develop a blood clot than non-pregnant patients.
• Peripartum cardiomyopathy: This is a rare condition in which the heart becomes weakened and enlarged during the last month of pregnancy. The heart cannot pump enough blood to the body.

At UNM Hospital, we created a Special Delivery team to help pregnant people with heart and other chronic conditions get the personalized services and care they need. Your high-risk pregnancy doctor carefully monitors your heart condition, discusses your options and helps you plan next steps.

If you are worried about a symptom—or if something feels off—call your doctor. Some normal pregnancy changes overlap with symptoms of heart conditions, so the safest choice is to get it checked out.

Not Normal Symptoms: Call the Doctor Now

Blurred Vision

Pregnancy hormones can cause minor vision changes during pregnancy. But this should not cause noticeable eye pain or vision loss. Sudden, major vision changes can be a symptom of high blood pressure, a heart condition or fluid retention in the brain (hydrocephalus), which can be life-threatening if not treated.

Call your healthcare provider if you notice sudden vision changes, such as:

• Auras (vision changes such as flashes of light, blind spots, zig zags or fuzzy lines)
• Blurry vision
• Flashing lights
• Light sensitivity
• Spots

Chest Pain

It is normal to experience occasional, minor discomfort in your chest while pregnant. Heartburn or indigestion can cause this. Sometimes you may feel slight pressure from the growing fetus pushing against your organs. However, it is not normal to experience chest pain.

Call 9-1-1 if you have sudden, severe chest pain. This can indicate a serious condition such as a heart attack, a blood clot in the lung or preeclampsia.

Talk with your doctor right away if you have any of these symptoms:

• Abnormal swelling
• Chest pain
• Fever
• Pain that radiates down either arm
• Persistent coughing
• Shortness of breath

Fainting

Fainting or blacking out (syncope) while pregnant could indicate that your heart is not pumping blood properly. It can mean your blood pressure might be low or you might have an irregular heartbeat (arrhythmia).

Racing Heart Rate

During pregnancy, you may feel like your heartbeat is fluttering or skipping a beat. Temporary heart palpitations do not always mean something is wrong. Palpitations can be caused by anxiety, stress or hormone changes.

But a racing heart rate is not normal. You can find your heart rate by counting the number of beats in 60 seconds that you feel on the inside of your wrist or the side of your neck. At rest, you should feel fewer than 100 beats per minute.

Call your doctor if you have any of the following:

• Bloody cough
• Palpitations lasting longer than 30 seconds
• Resting heart rate higher than 100 beats per minute
• Trouble breathing

These symptoms can indicate possible arrhythmia, preeclampsia or pulmonary hypertension (high blood pressure in the arteries leading to your lungs).

Swelling in the Hands or Feet

It is normal to have a small, gradual amount of swelling or puffiness (edema) in the hands, feet, legs, ankles or face while pregnant. This “water weight” comes from the increase in sodium levels and body fluids during pregnancy.

But a large amount of swelling that comes on fast can be a sign of a blood clot, heart failure or preeclampsia. If you experience rapid or painful swelling, call your doctor right away.

Common Changes During Pregnancy: Call If You’re Worried

Normal heart and blood vessel changes during pregnancy can cause some of the following symptoms. Call your doctor if you are worried about any symptoms you experience.

Dizzy or Lightheaded

Pregnancy hormones cause the walls of blood vessels relax to make room for the additional blood flow. You may feel a bit dizzy in the first and second trimesters of pregnancy because of normal changes in your blood pressure.

Your healthcare provider monitors your blood pressure throughout the pregnancy to check whether it is too high or low. In between your appointments, if you experience severe dizziness or if you faint, call your doctor right away.

Extra Tired

Feeling extra tired (fatigued) can be one of the first signs you are pregnant. Fatigue is also common in the third trimester of pregnancy due to hormone changes and an increased heart rate. Many pregnant people also get less sleep, making them feel less rested in general.

Healthy habits can help you get better quality sleep:

• Drink plenty of water throughout the day.
• Avoid caffeine.
• Eat balanced, nutritious meals throughout the day. If you feel hungry late at night, eat a light, protein-rich snack like cottage cheese with fresh fruit.
• Go to bed at the same time every night to establish a consistent sleep pattern.
• Avoid TV, computer and mobile phone screens for an hour before bed.

While feeling more tired than usual during pregnancy is normal, extreme fatigue is not. Persistent, ongoing or severe fatigue can indicate an underlying health condition. See your healthcare provider if you experience severe fatigue.

Heart Murmur

A heart murmur is a whooshing or swishing sound in your heartbeat caused by a rush of blood through the heart. A doctor can hear a heart murmur through a stethoscope. It is common in pregnancy because of the increased volume of blood flowing through the heart.

Changes in heart sounds often begin around 12-20 weeks of pregnancy and disappear within a week after delivery. Most heart murmurs that develop during pregnancy are harmless. But heart murmurs should always be checked by a doctor because it is possible for them to signal a problem with the heart. If so, a cardiologist will follow up with additional tests and treatment.

Shortness of Breath

It is normal to feel like you can’t catch your breath when doing certain activities like going up a flight of stairs. Early in the pregnancy, this can be caused by hormonal changes. Later in the pregnancy, the uterus pushes upward on the lungs, causing you to take more shallow breaths. Conditions such as asthma or COVID-19 can also cause shortness of breath or make it worse.

Call your healthcare provider right away if your shortness of breath is severe or suddenly gets worse, your lips get blue or if you have pain while breathing. That may indicate something other than pregnancy is disrupting your breathing. If you experience chest pain, call 911.

Compassionate Care for Heart Conditions in Pregnancy

Heart conditions are serious during pregnancy and need the care of a high-risk pregnancy doctor. It is important you attend all recommended prenatal appointments because proper care can help increase the possibility for a healthy pregnancy and delivery.