Pregnancy brings lots of changes. Besides the obvious ones like a growing belly, there are some that aren’t as noticeable. One example is an increased amount of blood in the body.

This extra blood results in a heart rate that’s about 25 percent faster than usual. A faster heart rate can result in occasional heart palpitations. These feel like your heart is fluttering or beating extremely fast.

Heart palpitations can be normal and nonharmful during pregnancy. But there’s always a chance they could mean you have a more serious, underlying health condition.

Read on for what you should know about pregnancy and heart palpitations.

The heart has a lot of work to do when you’re growing your baby. You must increase your blood supply to provide your baby with blood needed to help them grow and develop.

By the time you’re in your third trimester, about 20 percent of your body’s blood will be going toward your uterus. Because your body has extra blood, the heart has to pump faster to move this blood through. Your heart rate may increase by 10 to 20 extra beats per minute.

In the second trimester, blood vessels in your body start to dilate or get bigger. This causes your blood pressure to lower slightly.

When your heart has to work harder, some abnormalities can result. This includes unusual heart rhythms like heart palpitations.

Women experience heart palpitations differently. Some may feel lightheaded or uneasy, like their heart is pounding especially hard. Some might feel like the heart is flip-flopping in the chest.

Whatever your symptoms, there are several different potential causes of heart palpitations when you’re pregnant. These include:

  • anxiety or stress
  • effects of increased blood volume
  • something you’ve eaten, like food or drinks containing caffeine
  • cold and allergy medicines that contain pseudoephedrine (Nexafed, Sudafed Congestion)
  • an underlying heart disorder, such as pulmonary hypertension or coronary artery disease
  • heart damage from a previous pregnancy
  • an underlying medical problem like thyroid disease

Sometimes recognizing an underlying heart disorder is difficult during pregnancy. That’s because symptoms of a heart disorder can be similar to pregnancy symptoms. Examples include tiredness, shortness of breath, and swelling.

Throughout your pregnancy, you’ll see your doctor frequently. Appointments happen weekly as you near your due date. But if you seem to be regularly experiencing heart palpitations, they seem to be lasting longer, or seem to be more intense, call your doctor.

There are some symptoms that indicate you should seek emergency medical attention. These include heart palpitations that also occur with:

Your doctor will start diagnosing your heart palpitations by taking a medical history. If you’ve had palpitations before, have other known heart conditions, or have family members with heart problems, it’s important to speak up.

Your doctor will likely also perform some tests. These can include:

  • an EKG, which measures the electrical activity of your heart
  • wearing a Holter monitor, which watches your heart rhythms for a 24- to 48-hour period
  • blood testing to test for underlying conditions, like electrolyte imbalances or impaired thyroid function

Your doctor may order more specific tests based on these results.

If your palpitations aren’t causing severe symptoms and don’t seem to be the result of a serious condition, your doctor likely won’t recommend any treatment. Often, the palpitations will go away after you’ve had your baby and your body returns to its prepregnancy state.

Medications are available to help keep your heart in rhythm. Your doctor will consider potential risks to you and your baby from taking medicines. However, medications are often avoided in the first trimester, as this is when a baby’s organs are developing.

If your palpitations are due to a severe arrhythmia or out-of-rhythm heartbeat, your doctor may recommend a procedure called cardioversion.

This involves delivering a timed electric current to the heart to get it back in rhythm. Doctors consider this safe to perform during pregnancy.

While heart palpitations during pregnancy certainly aren’t fun, they’re usually harmless. But it’s still best not to ignore this symptom, so you should let your doctor know. They might want to perform tests to make sure you don’t have a more serious condition.

Treatments are available that can help keep you and your little one healthy.