Fetal arrhythmia: Diagnosis, causes, treatment, and more Health ConditionsHealth ConditionsAlzheimer's & DementiaAnxietyArthritisAsthma & AllergiesBreast CancerCancerCardiovascular HealthCOVID-19Dermatology & SkincareDiabetesEnvironment & SustainabilityExercise & FitnessEye HealthHeadache & MigraineHealth EquityHIV & AIDSHuman BiologyInflammatory Bowel DiseaseLeukemiaLGBTQIA+Men's HealthMental HealthMultiple Sclerosis (MS)NutritionParkinson's DiseasePsoriasisSexual HealthWomen's HealthDiscoverNewsLatest NewsOriginal SeriesMedical MythsHonest NutritionThrough My EyesNew Normal HealthPodcastsHow to understand chronic painWhat is behind vaccine hesitancy?The amazing story of hepatitis C, from discovery to cureNew directions in dementia researchCan psychedelics rewire a depressed, anxious brain?Why climate change matters for human healthToolsGeneral HealthDrugs A-ZHealth HubsHealth ToolsBMI Calculators and ChartsBlood Pressure Chart: Ranges and GuideBreast Cancer: Self-Examination GuideSleep CalculatorHealth ProductsAffordable Therapy OptionsBlood Pressure MonitorsDiabetic SuppliesFitness TrackersHome GymsGreen Cleaning ProductsHow to Shop for CBDQuizzesRA Myths vs FactsType 2 Diabetes: Managing Blood SugarAnkylosing Spondylitis Pain: Fact or FictionConnectAbout Medical News TodayWho We AreOur Editorial ProcessContent IntegrityConscious LanguageNewslettersSign UpFollow UsMedical News TodayHealth ConditionsDiscoverToolsConnectSubscribe What to know about fetal arrhythmiaMedically reviewed by Stacy A. Henigsman, DO — By Tabitha Britt on May 27, 2022A healthy fetal heart rate ranges between 110 and 160 beats per minute. A heart rate that is faster or slower than this may indicate that there is an issue that needs further attention. An arrhythmia, or irregular heartbeat, is when the heart beats too quickly, too slowly, or with an irregular rhythm. Fetal arrhythmia is an abnormal fetal heartbeat or rhythm. According to an article in the Indian Pacing and Electrophysiology Journal, the normal fetal heart rate ranges between 110 and 160 beats per minute (bpm). Doctors diagnose fetal arrhythmias in 1–3% of pregnancies. While most fetal arrhythmias are benign, certain cases may require medical intervention. This article explains how doctors diagnose a fetal arrhythmia, the different types, possible causes, and treatments. How is a fetal arrhythmia diagnosed Share on PinterestLuis Alvarez/Getty ImagesDoctors can detect fetal arrhythmias using ultrasound. If a doctor suspects an arrhythmia after reviewing a person’s routine ultrasound, they may recommend a fetal echocardiogram. A fetal echocardiogram (fECG) is a safe and noninvasive test that allows a pediatric cardiologist to see the structures of the heart. The test can take anywhere between 45 and 120 minutes, depending on the complexity of the fetus’ heart. Fetal magnetocardiography (fMCG) is not yet widely available. However, it can provide a more accurate picture of a fetus’ heart than fECG. Doctors can use fMCG to help diagnose heart arrhythmias in fetuses at around 20 weeks gestation and older. A doctor may also order further tests, such as: high-level fetal ultrasoundfetal magnetic resonance imaging (MRI) amniocentesis Learn more about arrhythmias here. Causes of fetal arrhythmia Sometimes, doctors cannot tell what is causing an arrhythmia. However, there are common causes, including:problems with the heart’s electrical signalsstructural abnormalities within the heartcongenital heart defectsrestricted blood flow to the heart, or ischemiaelectrolyte imbalance Types of fetal arrhythmia There are many types of fetal arrhythmias. They include: Extrasystoles or premature contractions PCs The most common type of fetal arrhythmia is premature contractions or PCs. This arrhythmia happens when the fetus has extra heartbeats, or ectopic beats, that originate in the atria (PACs) or the ventricles (PVCs). PVCs are less common than PACs. While most PACs are harmless and usually resolve over time, approximately 1% of fetuses with PACs will have significant structural heart disease. Another 0.5% will develop supraventricular tachycardia. Fetal PVCs also usually resolve over time. However, doctors will monitor them closely as they may lead to proxysmal ventricular tachycardias (VTs). Tachyarrhythmias Fetal tachycardia refers to a heart rate faster than 180 bpm. It might occur when a pregnant person:is dehydratedconsumes a lot of caffeinehas anxiety is taking sympathomimetic medications such as terbutalineis taking anticholinergic medicationsis in a state of ketosishas anemiahas an overactive thyroid Fetal supraventricular tachycardia (SVT) is the most common type of fetal tachycardia. It occurs when the fetus’s heart rate is faster than 220 bpm. SVT complicates approximately 1 in 1,000 pregnancies and may lead to hydrops or heart failure. Doctors may diagnose sinus tachycardia (ST) when a fetal heart rate is between 180 and 200 bpm. Atrial tachycardia (AT) occurs when the heart’s upper chambers, the atria, beat too quickly. Ventricular tachycardia (VT) occurs when the heart’s lower chambers, the ventricles, beat too rapidly and cannot pump enough blood around the body. AT is more common than VT. Bradyarrhythmias Doctors may diagnose fetal bradycardia when a fetus’s heart rate is under 110 bpm for 10 minutes or longer. Persistent fetal bradycardia is relatively rare, and causes include:congenital abnormalitiesdamage to the sinoatrial (SA) nodeion channel dysfunction, such as Long-QT syndromeinflammation and fibrosis of the SA nodeviral myocarditiscollagen vascular disordersmedications taken by the pregnant person, including beta-blockers and sedativesrare metabolic disorders, such as Pompes disease Approximately 30% of sustained bradycardia cases resolve without treatment. Types of fetal bradycardia include:sinus bradycardiablocked atrial ectopic beatsatrioventricular (AV) heart block Treatment of fetal arrhythmia Each case of fetal arrhythmia is different, and not all fetal arrhythmias require treatment. Many will resolve on their own. Doctors prescribe treatment based on the cause of the fetal arrhythmia, a pregnant person’s health, the fetus’ health, and the pregnancy stage. Medication is the most common way to treat a fetal arrhythmia. When a pregnant person takes medication, it passes through the placenta to the unborn baby. A pregnant person may take medications that include:digoxin flecainide sotalolamiodarone steroids such as dexamethasone and betamethasone After childbirth, doctors will monitor a baby’s heart rate carefully and may recommend further medication. Outlook Fetal arrhythmias are relatively common and account for 10–20% of referrals to fetal cardiology. The outlook for fetal arrhythmia depends greatly on the type and severity of the condition. PCs is the most common type of fetal arrhythmia. It has a good prognosis and does not affect the growth and development of the fetus. If doctors can make an accurate diagnosis of fetal arrhythmia, they can select the best treatments for a baby before and after its birth. Sustained fetal arrhythmias can lead to hydrops, cardiac dysfunction, or fetal demise. Where to find support To find out more about fetal arrhythmia and heart conditions that affect children, including finding support groups, a person can ask a primary physician or cardiologist for recommendations. Alternatively, they can visit: Arrhythmia AllianceChildren’s Heart FoundationMarch of DimesMended Hearts Summary Most fetal arrhythmias are benign and resolve on their own. Doctors usually diagnose fetal arrhythmias using a fetal echocardiogram. However, they may also use other tests. Doctors prescribe medication to treat fetal arrhythmias. They take various factors into account before choosing treatments, including maternal health and the severity of the condition. Untreated fetal arrhythmias can lead to hydrops, cardiac dysfunction, or death of the unborn baby. Doctors will monitor the health of the fetus and the pregnant person throughout pregnancy and after childbirth. A baby may require further treatment if the arrhythmia does not resolve on its own. Last medically reviewed on May 27, 2022Cardiovascular / CardiologyPediatrics / Children's HealthPregnancy / ObstetricsMedically reviewed by Stacy A. Henigsman, DO — By Tabitha Britt on May 27, 2022 Latest newsWhat sets 'SuperAgers' apart? Their unusually large neuronsOmega-3 may provide a brain boost for people in midlifeSeasonal affective disorder (SAD): How to beat it this fall and winterCDC: Monkeypox in the US 'unlikely to be eliminated in the near future'Why are more women prone to Alzheimer's? New clues arise Related CoverageCongenital heart disease and heart defectsMedically reviewed by Joyce Oen-Hsiao, MD, FACC A congenital heart defect is a type of congenital heart disease. It is a structural difference present from birth. Learn more here.READ MOREThe heart: All you need to knowMedically reviewed by Dr. Payal Kohli, M.D., FACC Here, learn about the structure of the heart, what each part does, and how it works to support the body. We also explore the electrical impulses and…READ MOREPregnancy complications: A guideMedically reviewed by Carolyn Kay, MD A person may experience complications throughout pregnancy. Learn more about some examples of pregnancy complications and how to treat them here.READ MORERemedies for swollen feet during pregnancyMedically reviewed by Meredith Wallis, MS, CNM, ANP Many women experience swollen feet during pregnancy. Read about the causes of swollen feet during pregnancy and the treatments and home remedies.READ MOREWhat is the link between dizziness and pregnancy?Medically reviewed by Debra Rose Wilson, Ph.D., MSN, R.N., IBCLC, AHN-BC, CHT Dizziness is common during pregnancy. Sometimes, it can indicate or cause a significant problem. Here, learn how to prevent it, when to see a doctor…READ MORE