Why Your Heart Might Race During Pregnancy

Pregnancy is an exciting time that sends your heart aflutter with love and nervous energy. After all, preparing for parenthood is no small feat. But if your heart is racing more than usual, it might not just be caused by thoughts of diapers, car seats, and tiny little toes.

Read on to learn more about the symptoms, causes, and when to call a doctor about a heart racing during pregnancy.

Are Heart Palpitations During Pregnancy Normal?

It's normal to experience a racing heart, also called heart palpitations, during pregnancy, thanks to all the changes happening to your body. In most cases, feeling your heart racing during pregnancy is temporary and harmless. However, there are times when heart palpitations can indicate something more serious that requires medical attention.

"During pregnancy, your heart works harder and pumps more blood in order to keep you healthy and help your baby grow," says Benjamin DiJoseph, DO, an OB-GYN at Inspira Medical Center in Vineland, New Jersey. "It's normal to experience an increased heart rate and even some abnormalities in rhythm."

Symptoms of Heart Palpitations During Pregnancy

During pregnancy, a racing heart feels just like it sounds. Symptoms of heart palpitations typically include the following:

• A pounding heart
• An irregular heart rate
• Feelings of fluttering in the chest

Causes of Heart Palpitations During Pregnancy

You can thank an increase in blood volume for those heart palpitations. According to the American Heart Association (AHA), blood volume in pregnancy is 20% to 100% higher than pre-pregnancy levels, though the typical increase is about 45%. This dramatic uptick in blood volume—which is needed to support a growing fetus—means that the heart must work harder to push all that extra blood through the body.

To accommodate the extra work, the heart increases the number of beats per minute (bpm), causing the fluttery racing heart sensation that's so common during pregnancy. The AHA says that over the course of pregnancy, the heart will increase its bpm by 10% to 25% above the person's baseline bpm. Interestingly, this increase appears to continue as the pregnancy progresses, peaking during the third trimester.

More serious causes of heart palpitations during pregnancy

In rare cases, however, heart palpitations during pregnancy may indicate an underlying condition such as atrial fibrillation, hyperthyroidism, or myocarditis, says Dr. DiJoseph. Other common causes of heart palpitations include dehydration, anemia, or blood clots, issues that pose more urgent problems.

Pregnancy is an incredible stress test for the heart, explains Amanda P. Williams, MD, MPH, FACOG, an OB-GYN at the California Maternal Quality Care Collaborative in Palo Alto, California. "Pre-existing heart conditions, especially abnormal heart valves or abnormal stretching of the heart muscle, known as cardiomyopathy, can show up for the first time during pregnancy and can lead to persistent palpitations," among other symptoms.

Risk Factors for Heart Palpitations During Pregnancy

Heart palpitations are common during pregnancy, and there are many factors that can increase your risk. Dr. DiJoseph says the following issues increase your risk:

• Anemia (low red blood cell count)
• Dehydration
• Hormonal changes
• Hypoglycemia (low blood sugar)
• Hypotension (low blood pressure)

What's more, if you have an existing heart condition, you may experience more cardiac symptoms while pregnant, explains Dr. DiJoseph. "You may also be more likely to experience heart palpitations during pregnancy if you have anxiety, depression, or body mass index (BMI) above 30," says Dr. DiJoseph.

Can a Racing Heart Affect the Fetus?

In most healthy, uncomplicated pregnancies, a racing heart or occasional heart palpitations are considered normal and will not affect the pregnant person or the fetus. "Almost always, the fetus is protected from harm from palpitations," says Dr. Williams.

Dr. DiJoseph agrees: "Most of the time, heart palpitations during pregnancy are not dangerous to the birthing parent or the fetus."

But while heart palpitations themselves aren't usually a concern during pregnancy, there can be risks if they're linked to another health condition. For example, if the heart palpitations are caused by an autoimmune thyroid condition, the fetus may have thyroid issues, too, explains Dr. Williams.

Likewise, if the palpitations are from a maternal health condition that decreases maternal oxygenation (the amount of oxygen in the blood), there's a decrease in oxygenation to the fetus, says Dr. Williams. Ultimately, the most important factor for fetal well-being is the health of the gestational parent, she adds.

Preventing Heart Palpitations During Pregnancy

For those with a low-risk, healthy, and uncomplicated pregnancy, preventing or reducing that racing heart feeling can be as simple as tweaking your daily activities. For example, slowing down a bit and reducing stress can help. However, for those with higher-risk pregnancies that include certain underlying health conditions, heart palpitations can present serious challenges to watch out for.

"Heart palpitations during pregnancy can sometimes be prevented and managed with simple lifestyle changes," says Dr. DiJoseph. He suggests that pregnant people who are concerned about that racing heart sensation during pregnancy try making a few healthy switches like these:

• Limiting caffeine and added sugar in your diet
• Quitting smoking (and vaping)
• Staying hydrated by drinking plenty of fluids
• Practicing deep breathing, meditation, and other relaxation techniques

And when getting up from supine positions (lying on your back), sit first for 30 seconds and then stand. This allows blood pressure, which is lower when you lie down, to acclimate more slowly to the standing position—and poses less risk of palpitations. Of course, always bring up any concerns you have with a health care provider.

Diagnosing Heart Palpitations During Pregnancy

To diagnose heart palpitations during pregnancy, a health care provider will likely do a full exam that includes a health history. They'll look at any underlying conditions that could affect your heart as well as your family medical history to see if there are hereditary risk factors to consider. The doctor may also want to run a few tests. These can include:

• A Holter monitor, which records your heart's rhythm and bpm for 12 to 48 hours
• An electrocardiogram (ECG or EKG), which checks the heart's rhythm and bpm
• Blood tests to screen for specific conditions such as electrolyte and fluid imbalance and anemia
  

Treatment for Heart Palpitations During Pregnancy

Heart palpitations during pregnancy are usually not serious, although they may feel unpleasant. For a racing heart caused by pregnancy-related blood volume increase, the symptom is temporary and will typically go away soon after giving birth.

In some cases, your doctor may prescribe medication that can help balance your heart rhythm. This is especially true if you have an underlying medical condition or if you're experiencing a pregnancy-related complication that affects your heart.

When to Call the Doctor

It's always a good idea to call a health care provider if you experience any worrisome symptoms, including a heart racing during pregnancy.

"You should always tell your doctor when you're experiencing changes or abnormalities in your heart rate, especially if they are recurring or happening often. Your provider can monitor your health, screen you for underlying conditions, and help manage your symptoms with medication and lifestyle changes," says Dr. DiJoseph.

Seek emergency medical care if you experience any of the following symptoms during pregnancy:

• Chest pain
• Difficulty breathing
• Dizziness
• Fainting
• Severe swelling
• Sudden and severe fatigue