Yes, many newborn heart murmurs are harmless transition sounds that fade as circulation matures.
Hearing the word “murmur” during a first exam can feel scary. In babies, the term usually means a gentle whooshing picked up by a stethoscope during blood flow. Many infants have these sounds in the first days or weeks. Plenty are harmless and clear on their own. A smaller share points to a heart condition that needs attention. This guide explains what those sounds mean, when they are routine, and when to ask for extra checks.
Newborn Murmurs In Plain Terms
A murmur is an extra sound created by turbulent flow through valves or nearby vessels. In babies, the chest wall is thin and heart rates are fast, so even small flow changes can be heard. Clinicians grade loudness from 1 to 6. Grade 1 is faint; grade 6 can be heard without pressing the stethoscope to the chest. Loudness alone does not prove trouble, but it guides the next steps. For a clear definition and background, see the plain-language overview on MedlinePlus.
How Common Are Murmurs In Infants?
Murmurs are frequent in childhood. Many healthy kids will have one at some point. In the newborn period, a soft sound can show up while circulation shifts from womb life to lung life. Most infants with a soft, brief sound feed well, breathe comfortably, and go home with a plan to recheck at clinic visits. Pediatric and primary-care reviews note that the majority of childhood murmurs are benign, and that all infants are screened for critical defects with oxygen checks before discharge. National summaries for clinicians describe this approach and the high rate of innocuous findings, along with a standard oxygen screen (pulse oximetry) for every baby; see this clinical review from family medicine for context on routine newborn screening with pulse oximetry: evaluation guidance for heart murmurs in children.
Typical Types You’ll Hear About
Doctors often split murmurs into two buckets. Innocent (also called “physiologic”) murmurs come from a normal heart and normal blood flow during the newborn transition. Pathologic murmurs hint at a structural issue in the heart or great vessels. The table below gives a quick map of common newborn patterns.
| Murmur Type | Usual Timing/Location | What It Often Means |
|---|---|---|
| Innocent PPS (peripheral pulmonary stenosis) | Soft, left upper chest; radiates to back/axillae; early months | Branch pulmonary arteries are still small; fades by 6–12 months (see patient info) |
| Transitional flow across closing ductus | Left upper chest in first days | Sound during normal closure of the ductus arteriosus soon after birth |
| Small VSD or ASD | Holosystolic (VSD) or fixed split S2 (ASD) | Small holes between chambers; may close over time or need follow-up |
| Outflow obstruction | Ejection murmur with a thrill; neck radiation | Possible aortic or pulmonary valve narrowing; needs specialist review |
| Regurgitant lesions | Holosystolic or diastolic quality | Valve leak or rare defects; prompt cardiology input |
Are Newborn Heart Murmurs Typical? Signs And Checks
Yes, many are part of normal transition. Fetal circulation uses a duct and a foramen to bypass the lungs. After birth, those shunts close and flow redirects through the lungs. That period creates extra sounds in many babies. Clinicians still listen closely, run oxygen checks, and look at feeding, breathing, and color. The goal is simple: find the few babies who need treatment while reassuring everyone else. The American Heart Association page on murmurs explains the idea of “innocent” sounds that do not reflect disease.
What Clinicians Do At Birth And Before Discharge
Every infant gets a pulse oximetry screen for critical heart disease. This quick sensor on hand and foot checks oxygen levels. A low or uneven reading can flag problems so the team can act early. Babies also receive a full exam. If a murmur is present, the clinician notes timing, pitch, and where it is heard best. Those clues steer next steps, such as watching, ordering an echocardiogram, or calling a pediatric cardiologist. That blend of bedside exam plus oxygen screening is part of modern newborn care across hospitals and is reflected in clinical guidance for front-line teams (pulse-ox screening recommendation).
Why Innocent Murmurs Happen In New Babies
One common newborn pattern is called PPS. The letters stand for peripheral pulmonary stenosis. In the early months, the branches of the lung artery are still small. Blood moving from the larger main vessel into smaller branches can make a soft sound that spreads to the back. As the branches grow, the sound fades. That time course is one reason clinicians feel comfortable watching a well baby with this pattern. For a parent-friendly explainer on PPS, see this brief page from a children’s heart program: innocent PPS murmur.
When A Murmur Signals A Heart Problem
A minority of babies have a murmur linked to a defect. Examples include a ventricular septal defect (a hole between the lower chambers), an atrial septal defect (a hole between the upper chambers), valve narrowing, valve leaks, or outflow tract problems. Some small holes close on their own. Others need medicine or a procedure. The plan depends on symptoms, oxygen levels, and the echocardiogram.
How Doctors Sort Innocent From Pathologic
History and exam come first. Feeding pattern, breathing rate, color, and growth tell a lot. The stethoscope adds pitch, timing, and radiation. Oxygen saturation helps catch hidden low oxygen. If questions remain, an echocardiogram shows structure and flow in detail. In many nurseries, a baby with a concerning sound or low oxygen will get an urgent scan before discharge. A short clinic wait can feel long, so teams try to answer the big questions early and plainly.
Red Flags That Need A Same-Day Call
Most newborns with a soft, short murmur feed well and breathe easily. Call your clinician fast if you see any of these: blue lips or tongue, fast breathing, poor feeding, sweating with feeds, puffy legs, weak pulses, long pauses during sleep, or a baby who seems floppy or hard to wake. These signs can point to low oxygen, heart strain, or infection. A quick exam and oxygen test can sort out what’s going on. Parent leaflets from hospital trusts stress the same list of warning signs and the plan for prompt review at any time.
What Parents Can Expect After The First Week
Plenty of murmurs fade during the first clinic visits. If the sound persists at the six-week check, your clinician may order an echocardiogram or refer to cardiology. Infants with a known small defect often just need routine growth checks. Many play, feed, and develop like any other baby while the team watches over time.
Evidence-Backed Checks You May Hear About
Pulse oximetry: a painless light sensor on hand and foot that flags low oxygen and helps catch critical defects early. Echocardiogram: a scan that uses sound waves to show chambers, valves, and flow. It’s the main test when a sound is concerning or sticks around. Electrocardiogram: a rhythm test that helps with electrical patterns; it doesn’t rule out many structural issues by itself in newborns. Your team will choose the right mix based on the bedside picture and the pattern of the sound.
Follow-Up Timeline And Who Is Involved
Care often starts with your midwife, GP, or pediatrician in the first days at home. Many areas schedule a six- to eight-week check where the heart is reviewed again. If the sound persists or if symptoms show up, the next step is a pediatric cardiology visit. There, a focused exam and an echocardiogram settle most questions on the same day. If a small defect is found, you’ll get a plan for visits and a clear list of signs that should trigger a call.
Risk Factors That Raise Suspicion
Certain clues raise the chance of a true defect: a strong family history of congenital heart disease, maternal diabetes, some infections during pregnancy, exposure to certain medicines, or a known genetic syndrome. Any of these paired with a murmur usually leads to an early cardiology review.
What The Grades And Terms Mean
You may hear terms during the exam. “Systolic” means the sound occurs when the heart squeezes. “Diastolic” means it occurs when the heart relaxes; diastolic sounds often lead to a deeper look. “Thrill” means a vibration felt by hand on the chest. “Click” can point to a valve issue. These words are just clues. The echocardiogram gives the full picture when needed.
Care Pathways: Watchful Waiting Vs. Action
Babies with a well baby exam, good oxygen levels, and a soft pattern often just need watchful waiting. The sound fades as the chest wall thickens and lung vessels grow. If the exam shows a harsh sound, a thrill, or a second heart sound that stays fixed, the team moves faster with imaging and referral. The aim is right-sized testing: not too much for well babies, not too little for the few who need help.
Day-To-Day Life With A Benign Pattern
There is no need to limit tummy time, baths, or travel for an infant who is feeding well and has a benign sound. Tiredness with feeds can happen in many babies for simple reasons like latch or reflux. If feeds are slow every time, or if weight gain stalls, bring that up early at clinic visits. Keep vaccination visits on schedule and share any new signs you’ve noticed.
Myths And Facts
- “A murmur means a weak heart.” Not in many babies. A soft newborn sound often comes from normal transition.
- “Sports or tummy time should stop.” Not for an innocent pattern. Activity limits apply only with specific defects and a specialist plan.
- “Every murmur needs medicine.” Medicine helps certain defects. A purely innocent sound needs no treatment.
- “All murmurs are permanent.” Many fade as vessels grow or as small holes close over time.
Questions To Ask Your Clinician
- Where on the chest is the sound heard best, and during which part of the heartbeat?
- How strong is it on the 1–6 scale, and does it radiate to the back or neck?
- Was the oxygen screen normal in both limbs?
- Does my baby need an echocardiogram now, or is watchful waiting reasonable?
- What signs should trigger a same-day call?
Decision Guide: What To Do Next
| Situation | Next Step | Why It Helps |
|---|---|---|
| Soft early murmur, baby well, oxygen normal | Watch and recheck at routine visit | Many sounds fade as vessels grow |
| Murmur plus low oxygen or blue color | Immediate assessment and echo | Screen for critical defects and treat early |
| Murmur with poor feeds or fast breathing | Same-day clinic visit | Check for heart strain, infection, or other causes |
| Known small VSD/ASD without symptoms | Growth checks and planned echo | Track closure and heart size over time |
| Family history or genetic syndrome | Early cardiology referral | Higher chance of structural change |
Key Takeaways For Parents
Murmurs in babies are common. Many come from normal transition and fade. Screening with pulse oximetry and a careful exam catches most serious problems early. If your baby is well, feeds well, and has normal oxygen, watchful waiting is common. If you ever see trouble signs, seek care the same day. For a clear, plain-language overview of harmless childhood murmurs, the American Heart Association page on murmurs is a helpful reference to share with family.