Pregnancy

Palpitations in Pregnancy: A Racing Heart, Decoded

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Heart palpitations are common in pregnancy because blood volume expands and the heart rate rises to supply the baby. Brief flutters and occasional skipped beats are usually harmless, most noticeable later in pregnancy. Palpitations with chest pain, breathlessness at rest, fainting, or a fast heartbeat that will not stop need prompt medical evaluation.

Last updated: July 2026

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Why does pregnancy make your heart race?

Pregnancy places a large, steady extra workload on the heart, and feeling it is normal. Blood volume rises substantially — by roughly 40% to 50% in typical estimates by the later months — so the heart pumps more with each beat, and the resting heart rate climbs. Hormonal shifts add to the pounding or fluttering sensation. According to the Office on Women's Health, a higher heart rate is an expected change of pregnancy 1. These feelings usually grow through the second and third trimesters as demands peak, and they are often most noticeable when resting quietly or lying down. On their own, brief palpitations are typically harmless.

Which palpitations are usually harmless?

Most palpitations in pregnancy are benign and share a reassuring pattern. Brief flutters, an occasional skipped or extra beat, and a short burst of fast heartbeat that settles within 1 to 2 minutes are the common, low-risk types. They often surface when lying down, after a caffeinated drink, when anxious, or when dehydrated — everyday triggers that also affect people who are not pregnant. Our overviews of what causes palpitations and caffeine and palpitations explain these patterns. Palpitations that are fleeting, occasional, and unaccompanied by other symptoms rarely signal a heart problem. Cutting back on caffeine and staying hydrated often reduces how often they occur.

Could palpitations mean anemia or thyroid trouble?

Two common and treatable conditions can amplify palpitations in pregnancy: anemia and thyroid disorders. Iron-deficiency anemia makes the heart beat faster and harder to move oxygen with fewer red cells, and it is common in pregnancy, which is why ACOG recommends routine screening 2. An overactive thyroid can also cause a racing heart, tremor, and heat intolerance, and thyroid disease affects a meaningful minority of pregnancies, so guidelines support testing when symptoms suggest it 3. Both are found with simple blood tests and respond well to treatment. It helps to know whether palpitations reflect a real heart issue or anxiety, since anxiety is another frequent, benign driver. A clinician can sort the causes efficiently.

When do palpitations need a workup?

Certain palpitation patterns move from reassuring to worth investigating. A fast heartbeat that will not slow, palpitations with chest pain, breathlessness at rest, or fainting, or a sense of the heart truly racing for long stretches all warrant evaluation. Palpitations that wake you or occur at night when lying down can be normal but deserve a mention if frequent. A clinician may check blood pressure, order an ECG, sometimes a heart monitor worn over 24 hours, and review iron and thyroid labs. The National Heart, Lung, and Blood Institute notes that heart symptoms in women are sometimes dismissed, so describing them clearly matters 4. A pre-existing heart condition raises the priority for assessment.

When palpitations in pregnancy need a clinician

A few features turn palpitations into a reason for prompt care rather than watchful waiting. Palpitations with chest pain, severe shortness of breath at rest, fainting, or a racing heart that will not stop can signal a rhythm or cardiac problem and warrant urgent evaluation. Palpitations alongside a blood pressure at or above 140/90, a bad headache, or vision changes point toward preeclampsia and need a prompt check 5. Even without these, palpitations frequent or distressing enough to disrupt daily life are worth raising. Gale can help you log the timing, triggers, and symptoms so your obstetric clinician can act on a clear picture.

Common questions

Usually, yes. Blood volume expands and the resting heart rate rises to supply the baby, so the heart works harder and palpitations — brief flutters or occasional skipped beats — are common and typically harmless, especially in the second and third trimesters.

Seek prompt care if palpitations come with chest pain, severe breathlessness at rest, fainting, or a fast heartbeat that will not stop. Palpitations with high blood pressure, a severe headache, or vision changes also need urgent evaluation, and a known heart condition raises the priority.

Yes. Iron-deficiency anemia and an overactive thyroid both speed up the heart and are common enough that clinicians screen for them. Simple blood tests can identify either, and both respond well to treatment.

Caffeine is a common, benign trigger for palpitations, and cutting back often reduces them. Staying hydrated helps too. If palpitations continue despite these changes, or come with other symptoms, a clinician can check for causes like anemia or thyroid problems.

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Palpitation warning signs in pregnancy

  • —Palpitations with chest pain, pressure, or pain spreading to the arm or jaw are a reason to call 911 or seek emergency care.
  • —A racing heart that will not slow, or palpitations with fainting or severe breathlessness, is a reason to seek urgent medical evaluation.
  • —Palpitations with a blood-pressure reading at or above 140/90, a severe headache, or vision changes are a reason to contact your obstetric clinician promptly.
  • —Palpitations alongside a known heart condition, or that are new and persistent, are a reason to schedule a prompt clinician review.

If palpitations come with chest pain, trouble breathing, fainting, or a racing heart that will not stop, call 911 or go to the nearest emergency room.

This article is general health education, not medical advice. Whether palpitations need testing should be evaluated by your obstetric clinician, who can check your heart rhythm, blood count, and thyroid.

References

  1. 1.Office on Women's Health (U.S. HHS) (2025). Prenatal care. Office on Women's Health (womenshealth.gov), U.S. HHS. link ✓An increased heart rate is an expected cardiovascular change of pregnancy as the heart works harder to supply the placenta.
  2. 2.American College of Obstetricians and Gynecologists (2021). Anemia in Pregnancy: ACOG Practice Bulletin, Number 233. Obstetrics & Gynecology. doi:10.1097/AOG.0000000000004477 ✓Iron-deficiency anemia is common in pregnancy, can cause a faster, harder heartbeat, and is identified by routine screening.
  3. 3.American College of Obstetricians and Gynecologists (2020). Thyroid Disease in Pregnancy: ACOG Practice Bulletin, Number 223. Obstetrics & Gynecology. doi:10.1097/AOG.0000000000003893 ✓Thyroid disease in pregnancy, including overactive thyroid, can cause a racing heart and related symptoms; guidance supports testing when symptoms suggest it.
  4. 4.National Heart, Lung, and Blood Institute (2024). Coronary Heart Disease – Women and Heart Disease. National Heart, Lung, and Blood Institute (NHLBI), NIH. link ✓Heart symptoms in women are sometimes overlooked or dismissed, underscoring the value of describing palpitations and related symptoms clearly.
  5. 5.American College of Obstetricians and Gynecologists (2020). Gestational Hypertension and Preeclampsia: ACOG Practice Bulletin, Number 222. Obstetrics & Gynecology. doi:10.1097/AOG.0000000000003891 ✓Preeclampsia is marked by blood pressure at or above 140/90, often with headache or visual changes, and warrants prompt evaluation.

5 sources, numbered by first appearance. General health information, not medical advice. AI-assisted editorial content — every citation independently verified. Editorial policy

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