What a Failure to Thrive Diagnosis Really Means for Your Child?

Affecting up to 10% of all children under the age of 2, a failure to thrive diagnosis can be scary—but is it, really? We asked several experts to weigh in.

baby in bassinet at hospital
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Millions of children are diagnosed with failure to thrive, or FTT, each year. According to one study, failure to thrive affects up to 10% of children under the age of 2 in high income countries. But while the word "failure" leaves many parents feeling frightened—when my own son was diagnosed with FTT in 2019 I was terrified; I felt like a bad parent and didn't know what to do—the term is just that: a medical term, one use to denote a specific state of being or existence.

But what is FTT, really? Should parents be concerned? Here's everything you need to know about failure to thrive, from what causes it to how it really affects children.

What Is Failure to Thrive?

While many assume failure to thrive is a disease and/or disorder, Cherilyn Cecchini, M.D. and board-certified pediatrician with Your Doctors Online explains that that is not the case. "Failure to thrive is not a disease or disorder," says Dr. Cecchini. "Rather, it is a phrase used to describe infants who are not gaining weight as they are expected to."

Doctors diagnose children with failure to thrive when they do not grow along a certain curve or scale. "Pediatricians use charts to determine if a baby is growing well," she adds. "And there is typically a concern when an infants weight and height decrease below the 5th or 3rd percentile or shows a downward shift in growth across major percentiles on two occasions."

What are the Signs of Failure to Thrive?

While numerous things can be a sign of failure to thrive, a FTT diagnosis is usually based on height and/or weight fluctuations. "Infants or children who fail to thrive have a height, weight, and head circumference that do not match standard growth charts," explains an article from John Hopkins Medical Center. Still, there may be signs and symptoms, including:

  • Poor suckling
  • Difficulty feeding
  • Fussiness
  • Weak cry
  • Stiff or "floppy" muscles

Children with FTT may also struggle to hold down nutrients and/or food, i.e. excessive vomiting and diarrhea can lead to failure to thrive.

What Causes Failure to Thrive?

There are numerous reasons why a child may be diagnosed with failure to thrive According to the Children's Hospital of Philadelphia, FTT can caused by an underlying medical condition. "A child who is unable to absorb enough calories (such as with severe allergies or a medical condition like cystic fibrosis) will... not grow as expected. Any condition that causes a child to need more calories than normally expected may also lead to failure to thrive," the article by Children's Hospital states. A lack of nutrients can also lead to FTT. This means the child is not ingesting enough calories or is not digesting them correctly.

How Is Failure to Thrive Diagnosed?

While it may seem like a failure to thrive diagnosis is fairly straightforward, it takes time for FTT to be diagnosed—mainly because failure to thrive is diagnosed by comparing a patient's growth history.

If a problem is suspected and/or if your child is not growing along their projected curve, their pediatrician may order additional tests. Blood work may be recommended, and urine samples may be collected. Their health and feeding history will also be discussed. And doctor's will work to determine and treat underlying causes, like allergies, thyroid issues, and/or chromosomal disorders.

How Is Failure to Thrive Treated?

According to Rebekah Diamond; a pediatric hospitalist in New York City, assistant professor of pediatrics at Columbia University, and author of the forthcoming book Parent Like a Pediatrician; the treatment of failure to thrive depends on what the diagnosis is. "The underlying cause of the issue must be discovered," says Dr. Diamond. "Once the cause of poor weight gain is diagnosed, your team of doctors, nutritionists, and pediatric specialists will all work together to make sure your kid gets the nutrition they need."

Should Parent Be Worried, i.e. What Does a Failure to Thrive Diagnosis Really Mean?

While receiving a FTT diagnosis can be disconcerting, Dr. Diamond urges parents not to worry. "Failure to thrive is more of a symptom, and it just means that more investigation needs to happen. It's always understandable to be anxious," she adds. "But there's no need to worry excessively." And Dr. Cecchini agrees.

"A failure to thrive diagnosis can be extremely unsettling—especially because the underlying reason often isn't known at first," says Dr. Cecchini. This causes many parents to fear the worst. It also makes many caregivers question themselves, wondering what that did wrong. However, "while scary, a FTT diagnosis does not mean that parents have failed. Working with a dedicated medical team, including a pediatrician, social workers, nutritionists and other specialists is important. Together, there are ways to determine the cause and to help your child meet their growth goals."

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