Heart Murmurs Are Actually More Common in Babies Than You Would Think
When I trained to work as a labor and delivery nurse, one of the things that I was taught to look for were heart murmurs in newborns. It was a skill that I tried very hard to develop, but I have to admit that it was a difficult one to fully hone. There was a nurse at the hospital I worked at however, who was phenomenal at detecting heart murmurs, even the very hard-to-hear ones.
She had a special stethoscope for finding them, an ear for listening, and most importantly, she took the time to thoroughly assess every single newborn, even ones that had been “cleared” by other nurses. And more often than not, she found heart murmurs that other nurses, myself included, would miss.
Finding a heart murmur in a newborn at a hospital might sound like a very scary thing — and to a lot of families at the hospital who were told their baby might have a murmur, it is overwhelming. But the truth is, newborn heart murmurs are actually a lot more common than you would think — here's why.
First up, what is a heart murmur? A heart murmur occurs when blood “leaks” through one of the heart's valves or when blood flows through a narrowed or stiffened artery. Heart murmurs themselves are not dangerous and do not need treatment, but there may be a need for medical treatment depending on what is causing the heart murmur.
As one 2014 study revealed, doctors and nurses take cardiac (heart) assessments in the newborn stage very, very seriously because 1) heart murmurs are one of the first signs of a more serious heart defect 2) heart defects are one of the most common forms of birth defects, affecting about 0.8 to 1% of babies per 1,000 live births and 3) like any other type of medical complication, the earlier you catch it, the better.
But heart murmurs in newborns can also be tricky because they can indicate one of two things: that there is a serious problem with the baby's heart or 2) that there is nothing at all wrong with the baby's heart. The data shows us that heart murmurs are one of the first signs of heart problems in newborns, but that not all babies who have heart murmurs have an actual heart issue.
Confusing? Yup, I know.
The reason that a newborn heart murmur might indicate that there is nothing wrong at all is simply because, after birth, it can take some time for the baby's circulatory and cardiac systems to regulate. You probably already know that before a baby is born, he or she receives oxygen from the mother through the umbilical cord, and not through the lungs. At birth, however, the baby's lungs start working and their heart valve is supposed to close in order to adapt to the new way of circulating oxygen.
As you can imagine, sometimes that whole process takes some time and adjusting and as a result, a harmless murmur may be present in the newborn stage as the baby's body adapts to its new circulatory system. In one study review, it's stated that 1% of all newborns will have a heart murmur and of that one percent, anywhere between 31 and 86 percent had a more serious heart defect.
And obviously, any infant with a history of heart defects or heart disease in the family, or any other symptoms, such as extreme lethargy or not being able to eat, may be more at risk as well. In most cases, however, heart murmurs in children are described as “innocent,” meaning they may not have a discernible cause and they do not require any treatment — one study found that 61% of all children found to have murmurs were eventually classified as innocent murmurs.
The moral of the story? If you are told in the hospital that your newborn baby has a heart murmur, don't panic. In some cases, the murmur may resolve on its own as your baby grows. If your baby's heart murmur persists, you will follow up with a pediatrician for further testing to determine if it may have a structural cause that can be corrected.
Were you ever told your baby had a heart murmur?