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Heart murmur

Heart murmurs in a healthy newborn baby

The doctor or our advanced nurse practitioner has heard a heart murmur during your baby’s routine newborn examination.

Parents may find this worrying and upsetting, but we would like to reassure you that the vast majority of these murmurs heard during the first few days of life disappear within the first few months.


What is a heart murmur?

A murmur is the medical term used to describe extra sounds that blood makes as it passes through the valves and blood vessels of the heart. It can be heard through a stethoscope between normal heartbeats.


What causes the murmur?

It is common for newborn babies to have heart murmurs in the first days of life.

  • It can be caused by fast blood flow through the heart, which is normal for babies.
  • The blood circulation system in the baby whilst inside the womb is different from the circulation system in the newborn baby. After birth, changes take place in the circulation pathways, and these can cause murmurs.
  • However sometimes, murmurs can also be caused by blood crossing through a hole in the heart, a valve that is too narrow, or a leak in a heart valve/structural heart problem.


What might happen to the murmur?

Most murmurs disappear as the baby grows. This is because the changes that were taking place in the blood circulation system are now complete.

In some babies, the murmurs can persist into childhood without anything being wrong with the heart – these are called “innocent” or “functional” murmurs.

In some babies there can be problems with the heart but this is usually associated with other problems, which may become apparent in the first few days of life, such as rapid breathing, feeding difficulties, blue lips and failure to gain weight. In some babies there can be no symptoms or signs, apart from a heart murmur.


What happens next?

Our team will discuss with you what the next best course of action will be for your baby; this depends on our assessment of your baby. You will be encouraged to ask about all your concerns and our team will try their best to answer your questions.

We will also be informing your GP about the heart murmur. Your baby will be seen in clinic by a senior paediatrician in a few weeks’ time. If the murmur is still present in a few weeks, the paediatrician will refer your baby to be seen in a cardiology clinic, which may include further tests. Your baby may get a scan of the heart, which should not cause your baby any discomfort.

If your baby becomes unwell in any way, please contact your GP or attend the Emergency Department for further advice

In particular we would like you to be aware of the following symptoms:

  • Is your baby feeling breathless, tired and disinterested to feed?
  • Has there been any change in his / her colour?
  • Is he / she excessively pale or blue?
  • Is your baby sweaty? Especially whilst feeding?
  • Your baby is inactive and sleepy
  • Your baby is breathless, breathing fast, or there is sucking in of the spaces between ribs
  • Your baby has clammy or cold skin.

None of these symptoms necessarily mean that your baby has a heart problem, but we feel it would be wise for a doctor to check that all is well. We would like to add that these symptoms should prompt parents to seek medical advice, regardless of whether or not a heart murmur has been heard.


Any further concerns:

If parents are concerned about any aspect of their baby’s health, please contact your GP surgery or contact NHS 111 for further advice.



British Heart Foundation -

Children’s Heart Federation